Compound cermetallic products and method of making them

The subject of the invention is a cermet composite body, a method of producing a cermet composite body, a cutting tip for a cutting tool with a cermet composite body, a cutting tool with a cermet composite body.

Cermetal is a term used to describe a monolithic material composed of a ceramic component and a binding component. The ceramic component contains non-metallic or metalloid syntax. The ceramic component is preferably combined in two or three dimensions. The binder component contains metal or alloy and is generally combined in three dimensions. The binder component bonds the ceramic component to form a monolithic material. Each of the properties of monolithic cermets is derived from the interaction of the characteristics of the ceramic component and the characteristics of the binder component.

The family of cermets is defined as monolithic cermets consisting of a specific ceramic component combined with a specific binding component. An example of a family is tungsten carbide bonded with a cobalt alloy (WC-Co family, cemented carbide). The properties of the cermet family can be adjusted, for example, by adjusting the quantity, individual characteristics, or the quantity and individual characteristics of each ingredient individually or together. However, improving the properties of one material invariably worsens another. For example, when the abrasion resistance improves in the WC-Co family, the fracture toughness deteriorates. Thus, in the shaping of monolithic cemented carbides, an endless cycle occurs that involves the improvement of one material property at the expense of another.

Despite this, monolithic cemented carbides are used in equipment exposed to aggressive abrasion, impact or both. However, instead of producing all equipment from monolithic cemented carbides, only selected parts of the equipment contain monolithic cemented carbide. These parts are exposed to aggressive abrasion, impacts or both. In some equipment, the cemented carbide part has a specific profile that should be able to maintain maximum equipment effectiveness. When a certain profile changes, the effectiveness of the equipment decreases. If the equipment is used for machining a workpiece, the portion of the removed, usable parts of the workpiece decreases as the cemented carbide profile deviates from the specified profile.

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For example, when specific carbide cutting blade profiles suitable for a mining machine operating continuously change, sharp cemented carbide cutting blades transform into blunt cemented carbide blades, hitting the coal seam and producing dust, coal dust and noise, rather than desirable coarse coal. When the tool is worn out, the power supplied by the motor driving the mining machine running continuously must also be increased.

One solution against changing the specific profile is to discontinue use of the equipment and change the cemented carbide profile. It is expensive because the equipment is not used when changing profile. Another solution involves scraping off the used part of the cemented carbide and inserting new cemented carbide. It is also costly because of not using the equipment when reinstalling and scraping off cemented carbide. If sintered carbides were made so that their specific profiles would be maintained, for example by self-sharpening, the economic and technical benefits would be significant.

The solution to the problem of a continuous cycle of regulating one property of a monolithic cermet at the expense of another is to combine several monolithic cermets to produce a multi-segment cermet product. Numerous attempts have been made in the world to improve multi-segment cemented carbide products. A number of publications are published in the US and foreign patent specifications regarding the subject. Part of many US and foreign patents include: US Patent Nos. 2,888,247; 3,090,895; 4,194,790; 4,359,355; 4,427,098; 4,722,405; 4,743,515; 4,820,482; 4,854,405; 5,074,623; 5,333,520; and 5,335,738; and foreign patents Nos. DE-A-3,519; Gb-A 806 406; EP-A-0 11 600; DE-A-3 005 684; DE-A-3 519 738; FR-A-2 343 885; GB-A-1 115 908; GB-A-2 017 153; and EP-A-0 542 704.

Despite the large number of solutions proposed, no multi-segment cemented carbide product is commercially available. Further, there are no satisfactory methods for producing products from multi-segment cemented carbides. Furthermore, there are no satisfactory self-sharpening cemented carbide products, not considering multi-segment cemented carbide products. In addition, there are no satisfactory ways of producing multi-segment cemented carbide products that are also self-sharpening.

Some publications only present "thought experiments" and wishes, as it was not possible to develop methods for producing such products from multi-segment cemented carbides. Other publications present complicated ways.

In known methods for producing articles from multi-segment cemented carbides, the initial components and / or the geometry of the unbaked solid are subjected to pre-treatment.

For example, a method of making multi-segment cemented carbide is known in which the initial components used to manufacture the multi-segment cemented carbide are independently formed as unbaked solids. Independently formed unbaked solids are sintered separately and, after grinding, combined, for example, by soldering, brazing or shrink-fit, to produce a multi-segment cemented carbide product.

In another known method for producing articles from multi-segment cemented carbides, independently formed unbaked blocks are assembled together and then sintered. Different combinations of the same ingredients that contain independently formed unbaked lumps react differently to sintering. Each combination of ingredients shrinks in a unique way. Each combination of ingredients reacts differently to sintering temperature, time, atmosphere, or any combination of these values. Only comprehensive pre-treatment of the forming dies and, in this way, the dimensions of the unbaked bodies allows folding followed by sintering. To enable pretreatment, an extensive database is required that includes data for various temperatures, times, atmospheres, or any combination of these quantities. Creating and completing such a database is characterized by exorbitant costs. To avoid these costs, carefully made control equipment is used

178 269 ​​process. However, it is also too expensive. In addition, when carefully made process control equipment is used, slight deviations from the recommended process parameters result in deficiencies. '

A method for producing articles from multi-segment cemented carbides is known in which sinter stoichiometric articles from monolithic cemented carbides are sintered. Their compositions are characterized by carbon deficiency and therefore sintered carbides contain an eta phase. Monolithic cemented carbide products are then exposed to a carburizing environment that interacts by eliminating the eta phase from the periphery of each product. In addition to the pre-treatment of ingredients, this method requires intermediate process steps and carburizing equipment. In addition, the resulting multi-segment cemented carbide products provide only small benefits, because when the carburized peripheral segment wears, their usefulness ends.

For the above reasons, there is a need for a cermet composite body that can be manufactured in a cheap way. There is also a need for multi-segment cemented carbide products that are also self-sharpening and can be manufactured in a cheap way.

The cermet composite body according to the invention having a first segment comprising a first ceramic component and a first binder and at least one second segment comprising a second ceramic component and a second binder is characterized in that the first ceramic component of the first segment comprises grains whose average size is included in the range from about 0.5 pm to about 8 pm, and the content of the first binder in the first segment is about 5% to about 10% by weight, and the second ceramic component of the at least one second segment comprises grains whose average size is smaller than the average grain size of the first ceramic component of the first segment and the content of the second binder in the second ceramic component of the at least one second segment is greater than the content of the first binder in the first segment. The first segment and at least one second segment are at least partially separated by at least one automatically formed boundary surface, wherein the boundary surface has a step change in the binder content in the first segment and at least the second segment.

The boundary surface at least partially intersects at least one outer surface of the cermet composite body.

The first ceramic component of the first segment and the second ceramic component of the second segment 'comprises at least one component of borides, carbides, nitrides, oxides, silicas, or mixtures thereof, solutions and combinations thereof.

The first ceramic component and the second ceramic component are selected at least one carbide of at least one metal from groups 3,4,5 and 6 according to IUPAC. The first ceramic component and the second ceramic component comprise at least one carbide of at least one metal among Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. The first ceramic component and the second ceramic component are preferably tungsten carbide.

The second average grain size in at least one second segment is from about 0.5 pm to about 8 pm, preferably from about 1 pm to about 5 pm, and particularly preferably from about 2 pm to about 5 pm.

The first binder of the first segment and the second binder of the second segment comprise at least one metal from groups 8, 9 and 10 according to IUPAC, mixtures thereof, alloys and combinations thereof.

The first binder of the first segment and the second binder of the second segment contain at least one metal of iron, nickel, cobalt, mixtures thereof and their alloys. Preferably, the first binder of the first segment and the second binder of the second segment comprise cobalt and its alloys.

The first binder of the first segment has an average free path from about 0.5 pm to about 2.5 pm. The second binder of at least one second segment has an average free path from about 0.5 pm to about 1.5 pm.

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The content of the first binder in the first segment is about 5.5% to about 8% by weight. The ratio of the volume of the first segment to the volume of at least one second segment is from about 0.25 to about 4. The hardness of the first segment is less than the hardness of the at least one second segment.

At the boundary surface there is a step change in the average tungsten carbide grain size between the first segment and at least one second segment.

The method of producing a cermet composite body according to the invention is that a first powder mix containing a first ceramic component selected with a first selected medium grain size and a first binder in a selected amount are prepared and at least one second powder mixture containing a second ceramic component is prepared. with a selected second average grain size, and a second binder in a selected quantity. After this, the first powder mixture and at least one second powder mixture are placed next to each other, forming at least one and at least partial - contact surface between two powder mixtures, and then heated next to each other at least two powder mixtures to a temperature of at least partially thickening them and bonding together in the form of a cermet composite body.

The method of the invention is characterized in that the first average grain size is selected in the range from about 0.5 pm to about 12 pm, and the amount of the first binder is selected in the range from about 5% by weight to about 15% by weight, whereas for the second blend powdered grains with a second average size smaller than the first average grain size of the first powder mix and selected in the range from 0.5 pm to about 8 pm are selected, and the amount of the second binder is selected by about 2% less than the amount of the first binder in the first powder mix and the first powder mix and at least one second powder mix are processed side by side forming a composite cermet body having a first segment having a first binder content from about 5% to about 10 % by weight, connected at least partially automatically formed boundary surface to at least one second segment with a content of a second binder greater than the content of the first binder when the binder content abruptly changes on the boundary surface.

A boundary surface is formed to intersect it with at least one surface of the cermet composite body.

At least one component from borides, carbides, nitrides, oxides, silicides, or mixtures thereof, solutions and combinations thereof is selected for the first ceramic component and the second ceramic component. At least one carbide of at least one metal from groups 3,4,5 and 6 according to IUPAC is selected for the first ceramic component and the second ceramic component. In a preferred embodiment, at least one carbide of at least one metal from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. is selected for the first ceramic component and the second ceramic component. For the first ceramic component and for the second ceramic component tungsten carbide is chosen.

A first average grain size in the range of about 3 pm to about 10 pm is selected, and a second average grain size is selected in the range of about 1 pm to about 5 pm, and preferably a first average grain size in the range of about 5 pm to about 8 pm, and the second average grain size is selected from about 2 pm to about 5 pm.

The amount of the first binder in the first powder mixture is selected in the range of about 9% by weight to about 10% by weight, and the first segment of the cermet composite body is formed with a first binder content of about 5.5% to about 8% by weight.

At least one metal from groups 8.9 and 10 according to IUPAC, their mixtures, alloys and their combinations are selected for the binder of the first powder mixture and at least one second powder mixture, preferably at least one metal from iron, nickel, cobalt, mixtures thereof and their alloys, especially cobalt and its alloys.

The first powder mixture and at least one second powder mixture next to each other form a solid by means of at least one press treatment10

178 269, slurry casting, dense casting, strip casting, injection molding, extrusion and combinations thereof. The shape is formed by pressing.

During at least part of the compaction at a given temperature, the first powder mixture and at least one second powder mixture are subjected to pressure.

When placing at least a portion of at least two powder mixtures next to each other, they are shaped into a solid of the selected shape.

According to the invention, the cutting tip for a cutting tool, with a cermet composite body, has a front portion with a surface extending radially outward and rearward along the longitudinal axis and a rear portion connected to the front portion and located behind it along the tip axis, the portion the front contains two segments, the first of which forms the leading surface of the front part and contains the first cermetic set and the second segment, adjacent to the first segment, forms the outer surface of the front part and contains a second cermetal set.

The inventive cutting tip is characterized in that the first cermetic set comprises a first ceramic component whose grains have a first average size in the range from about 0.5 pm to about 12 pm, and contains a first binder in an amount of from about 5% to about 10% by weight, and the second cermetic set contains grains having an average size from about 0.5 pm to about 8 pm and contains a second binder in an amount of from about 8% to about 15% by weight wherein the content of the first binder is less than the content of the second binder. The first grain size is larger than the second grain size and the first cermetic set of the first segment, with higher wear resistance, is located inside relative to the second cermet set of the second segment, with lower wear resistance, and is connected to it metallurgically at the boundary surface on which there is a step change in binder content between the first segment and the second segment.

The first segment projects forward beyond the second segment.

The hardness of the second cermetic set of the second segment is higher than the hardness of the first cermetic set of the first segment. The first cermetic kit and the second cermetic kit comprise tungsten carbide, and the first binder and the second binder are selected from the group consisting of cobalt and cobalt alloys. The first cermet and second cermet are free from eta.

The first cermetic set contains from about 5.5% to about 8% by weight of cobalt, and the second cermetal set contains from about 8% to about 15% by weight of cobalt. The first cermet set contains grains from about 3 pm to about 10 pm, and the second cermet set contains grains from about 1 pm to about 5 pm. The first cermet set contains grains from about 5 pm to about 8 pm, and the second cermet set contains grains from about 2 pm to about 5 pm.

The first ceramic kit has a hardness of at least 87 Rockwell A, and preferably has a hardness of at least 88 Rockwell A.

According to the invention, the cutting tool with a cermet composite body comprises an elongated holder having opposing front and rear ends and a cutting tip attached to the front end of the holder, the cutting tip comprising a front portion with a surface extending radially outward and rearward along the longitudinal axis and a connected rear portion with the front and rear behind it along the axis of the tip, which front has two segments, the first of which forms the leading surface of the front part and contains the first cermetal assembly, and the second segment, adjacent to the first segment, forms the outer surface of the front part and contains the second cermetal assembly.

The cutting tool according to the invention is characterized in that the first cermetic set comprises a first ceramic component whose grains have a first average size in the range from about 0.5 pm to 12 pm, and contains the first binder in an amount of from about 5% to about 10% by weight and the second cermetic set contains grains with an average size from about 0.5 pm to 8 pm and contains a second binder in an amount of from about 8% to about 15% by weight, wherein the content of the first binder is less than the content of the second binder, and the first grain size is larger than the second grain size and the first cermetic set of the first segment, with higher wear resistance, is located inside relative to the second cermet set of the second segment, with lower wear resistance , and is connected to it metallurgically at the boundary surface, where there is a step change in the binder content between the first segment and the second segment.

The first segment projects forward beyond the second segment in the cutting tip.

The hardness of the second cermetal set of the second segment is higher than the hardness of the first cermetal set of the first segment.

The first set of cermetals and the second set of cermets contain tungsten carbide, and the first binder and second binder are selected from the group consisting of cobalt and cobalt alloys. The first cermet set contains from about 5.5% to about 8% by weight of cobalt, and the second cermetalic set contains from about 8% to about 15% by weight of cobalt. The first cermetic set and the second cermet set are free from the eta phase.

The first set of cermetals preferably contains grains from about 3 gm to about 10 gm, and the second set of cermetals contains grains from about 1 gm to about 5 gm, and especially the first set of cermetals contains grains from about 5 gm to about 8 gm, and the second cermetic set contains grain sizes from about 2 gm to about 5 gm.

The first cermetic set has a hardness of at least 87 Rockwell A, and preferably at least 88 Rockwell A.

The present invention satisfies the long felt need in the field of cermets for improved composite bodies of metallic complex materials that provide uniform and controlled wear, giving the product in which they are used self-sharpening properties when used as a tool. Such multi-segment products are especially useful in abrasion applications. The advantage of joining at least two segments is ieeoliSe and controlled abrasion of such products, and thus extension of service life, because these unique characteristics maintain, for example, the cutting ability of the product when it is used as a cutting tool when the product is used during operation.

The method of the invention solves the problems encountered in the production of multi-segment products. Known multi-segment products had defects (e.g., cracking of the non-sintered lump during sintering), occurring during product compaction. The current method, based on the effects of synergistic process parameters (e.g., different carbide grain sizes, or different binder content, or different binder chemistry, or any combination of previous sizes), eliminates these disadvantages. The products have an extended lifetime compared to the lifetime of the products known for such applications as, for example, abrasion.

According to the invention, at least one property of each of the at least two segments is adjusted by varying the grain size of the ceramic component, or the chemistry of the ceramic component, or the binder content, or binder chemistry, or any combination of these sizes. These different properties of individual segments are density, color, appearance, reactivity, electrical conductivity, strength, fracture toughness, modulus of elasticity, transverse modulus of elasticity, hardness of thermal conductivity, coefficient of thermal expansion, specific heat, magnetic susceptibility, friction coefficient, resistance to abrasion, impact resistance, chemical resistance, and so on.

According to the invention, the size of these at least two segments can vary. For example, the thickness of the first segment relative to the thickness of the second segment may vary from the first segment consisting of the coating on the second segment to the second segment consisting of the coating on the first segment. Naturally, the first segment and the second segment may exist in substantially equal proportions.

The subject of the invention is shown in the embodiments in the drawing, in which Fig. 1 shows a fragment of the cermet composite body in cross section, Fig. 2A,

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2B, 2C, 2D, 2E and 2F show various examples of the implementation of products or parts of products in the form of cutting tips comprising a cermet composite body in perspective views with cross sections; Fig. 3A is a schematic cross-sectional view of the step of backfilling the cemented carbide charge into the body mold in the first embodiment of the method of the invention. 3B - schematically the step of pressing the cemented carbide charge in the form of the body in the first embodiment of the method according to the invention, Fig. 3C - the unbaked solid obtained according to the first embodiment of the invention, Fig. 4A - the sintered body made according to the first example of the method, in longitudinal section in a photomicrographic image, taken at about 3.4 times magnification, fig. 4B, 4C and 4D depict respectively photomicrographs taken at approximately 500-fold magnification of the boundary surface between the first segment and the second segment of the multisegment cermet body taken according to the first example of the method, Fig. 4E, 4F and 4G photomicrographic images, taken at approximately 1500-fold magnification, the boundary surface between the first segment and the second segment of the multisegment composite cermet body made according to the first example of the method, Fig. 5 A and 5B - results of binder concentration measurement using EdS techniques in function of the distance from the edge on two diameters of the body made by the method according to the first embodiment, fig. 6 shows the results of hardness measurements at various locations on the longitudinal section of a product made by the method of the first embodiment, Figure 7 a perspective view of a conical cutting insert with a partial section containing a body made by the method of the first embodiment; FIG. 8A, 8B and 8C show a comparison of tool profiles with bodies made by the method of the first embodiment of the invention (solid line) and previously known (dashed line) when 4 meters of carbon are used to make the tool, with respect to the initial tool profiles (dotted line); FIG. 9A, 9B and 9C - comparison of tool profiles with bodies made by the method according to the first embodiment of the invention (solid line) and previously known (dashed line) after 8 meters of carbon used for making, with respect to the initial initial profiles of the tool (dot line).

Figure 1 shows a cermet body 101 according to the present invention. Since this is a hypothetical cermet body, the line AA of Fig. 1 can show, for example, the boundary or surface of the cermet body, the mirror symmetry plane, the cylindrical or rotational symmetry axis. The following description assumes that the AA line is a border. It will be apparent to those skilled in the art that the following description is extended to cermet bodies having complex geometry. Thus, the following description should not be interpreted as a limitation, but rather as a starting point.

1, the cermet body 101 has a first segment 102, adjacent and integral with the second segment 103 or with at least one additional segment. It will be apparent to those skilled in the art that the cermet body of the present invention preferably includes multiple segments. The boundary surface 104 defines the contact border of at least two segments. In a preferred embodiment, the border surface 104 is formed automatically. The cermet body 101 has a front surface

105, defined by at least a portion of the first segment 102 and a recessed surface

106, formed by at least part of the second segment 103 or at least one additional segment.

Materials forming at least two segments are cermets. Such cermets contain at least one boride, carbide, nitride, oxide, silicide, mixtures thereof, their solutions or any combination of the above. The metal of at least one of the boride, carbide, nitride, oxide, silicon contains at least one metal of groups 2, 3 (including lanthanides and actinides), 4, 5,6,7,8,9,10,11,12,13 and 14 according to International Union of Theoretical and Applied Chemistry (International Union of Pure and Applied Chemistry - IUPAC). Preferably, the cermets contain at least one carbide, mixtures thereof, solutions thereof, or any combination of the above. The carbide metal is one or more metals from IUPAC groups 3 (including lantis and actinides), 4.5 and 6, more preferably one or more of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W; and even more preferably tungsten. The cermet binder for at least two segments consists of metals, glasses or ceramics, i.e. any material that produces or assists in the production of the liquid phase during sintering the liquid phases. Preferably, the binder comprises at least one metal from the IUPAC groups 8.9 and 10; preferably at least one of iron, nickel, cobalt, mixtures thereof and their alloys; and more preferably cobalt or cobalt alloys, such as tungsten cobalt alloys. The binders contain single metals, metal mixtures, metal alloys, or any combination of the above.

The size of the ceramic component, preferably the carbide (s) of at least two segments, is in the size range from a submicron to about 420 microns or more. The sub-micrometer includes ultra-fine and nanostructured materials. Nanostructured materials have structural dimensions ranging from about 1 nanometer to about 300 nanometers or more. The average grain size of the ceramic component, preferably carbide, in the first segment 102 is greater than the average grain size of the ceramic component, preferably carbide (s) in the second segment 102.

In a preferred embodiment, the grain size of the ceramic component, preferably carbide, and more preferably tungsten carbide of the first segment 102 is in the range of from about submicron to about 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns. Preferably, the grain size of the ceramic component of the first segment 102 is in the range of from about 0.5 microns to about 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns, while the average and grain size are in the range of about 0.5 micrometer to about 12 micrometers; preferably, from about 3 microns to about 10 microns; even more preferably, from about 5 microns to about 8 microns. Similarly, the grain size of the ceramic component of the second segment 103 is in the range of from about submicron to 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns. Preferably, the grain size of the ceramic component of the second segment 103 is in the range of about 0.5 microns to about 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns, while the average grain size is in the range of about 0.5 micrometer to about 8 micrometer; preferably, from about 1 micrometer to about 5 micrometers; even more preferably, from about 2 micrometers to about 5 micrometers.

The grain size of the ceramic component and the binder content are related to the mean free binder route, determined by quantitative metallographic techniques, such as those described in the work "Metallography, Principles and Practice", written by George F. Vander Voort 'a (published in 1984 by the McGraw Hill Book Company, New York, NY). Other techniques for determining the hard ingredient grain size include visual comparison and classification techniques such as those discussed in ASTM Standard B390-92, entitled "Standard Practice for Evaluating Apparent Grain Size and Distribution of Cemented Tungsten Carbide" tungsten carbide ”), approved in January 1992 by the American Society for Testing and Materials, Philadelphia, PA. The results of these procedures allow you to determine the grain size and size distribution.

In a preferred embodiment regarding ferromagnetic binders, the average grain size of the ceramic component, preferably carbide, and more preferably tungsten carbide, is dependent on the weight percentage of the binder (X_b), theoretical density (p, we play per cubic meter) and coercive (Hc, kiloamps per coil (kA / m)) segment of a homogeneous sintered cermet body segment, such as described by R. Porat and J. Malek in article entitled "Binder Mean-Free-Path Determination in Cemented Carbide by Coercive Force and Material Composition", published in the report of the Thrid International Conference of the Science of Hard Materials, Nassau, the Bahamas, November 9-13, l^and^^ 6, by Elsevier Applied Science and published by VK Sarin. For the cermet body made of cobalt bonded wol14 carbide

178 269 ​​fram, the calculated average grain size, d micrometres, of tungsten carbide, is given by equation 1.

d = 0.3 (164.822 / X_WhatPTH)^{l / 3}

H '(1)

In a preferred embodiment, the ratio of the average grain size of the ceramic segment of the first segment to that of the second segment is in the range of from about 1.5 to about 12, and is preferably in the range of from about 1.5 to about 3.

In a preferred embodiment, the binder content of the first segment 102 is, by weight, from about 2% to about 25%; preferably from about 5% to about 10%; and more preferably from about 5.5% to about 8%. Similarly, the binder content of at least one second segment 103 is in the range, by weight, from about 2% to about 25%, and more preferably from about 8% to about 15%. The binder content of the second segment 103 is greater than the first segment.

In a preferred embodiment, the combination of carbide grain size and binder content is associated with the binder mean free path, λ, as discussed in general by Vander Voort in detail, for ferromagnetic materials, by Porat and Malek. The average free path of the binder (λ micrometers) in a cermet body having a ferromagnetic metallic binder is a function of the binder weight percentage (X_b), coercive (Hc, kilo-ampere-meter per meter (kA / m)) segment of the homogeneous sintered cermet body and the theoretical density (pth, we play per cubic meter) of the segment of the homogeneous compact cermet body. For cobalt bonded tungsten carbide, the mean free path, λ, of cobalt binder is given by equation 2.

0,3X_Whatpth 890-Χ ^ pth

H_r

- | (164.822 / X_Whatpth) '(2)

In a preferred embodiment, the average free path of the binder in the first segment 102 is in the range of from about 0.5 micrometer to about 2.5 micrometer, and is preferably about 0.8 micrometer, while the average free path of at least one second segment 103 is in the range of from about 0.5 micrometer to about 1.5 micrometer.

The full geometric shape of the cermet body 101 is simple or complex, or any combination of the two. Full geometric shapes include cubes, parallelepipeds, pyramids, truncated pyramids, cylinders, hollow cylinders, cones, truncated cones, spheres (including fragments, segments and sections of the sphere, and spheres with cylindrical or conical holes), torus, cut cylinders, truncated cones, barrels, prisms, ellipsoids and combinations thereof. Similarly, the cross-sections of such metallic complexion bodies are preferably straight or complex, or may be a combination of both. Such shapes preferably include polygons (e.g. squares, rectangles, parallelograms, trapezoids, triangles, pentagons, hexagons, etc.). circles, rings, ellipses and their combinations. Figures 2A, 2B, 2C, 2D, 2E and 2F show combinations of the first segment 210, the second segment 211 and, in some cases, the third segment 212 (Fig. 2D), contained in products constituting cutting tips with different full geometries for use in various cutting tools. These figures show perspective views of products or parts of products with partial cross-sections, for example in the shape of a conical cap or conical hybrid. Fig. 2A shows the cermet body 201 as a cutting tip in the form of a ripper cone in Fig. 2B a second embodiment of the cermet body 202 constituting the cutting tip in the form of a compact element, in Fig. 2C the cermet body 203 constituting the cutting tip in the form of a grader blade or a scraper or planer, in Fig. 2D the cermet body 204 constituting the cutting tip in the form of a roof drill bit , in Fig. 2E, the cermet body 205 forming the cutting end in the form of a cutting insert for machining materials, and in Fig. 2F - the cermet body 206 constituting the cutting tip in the form of a conical pin or insert. All cermet bodies have a front surface 207 and an outer surface 208.

As shown in Figure 1, the boundary surface 104 forming the border between the first segment 102 and the second segment 103 divides the cermet body 101 symmetrically or asymmetrically, or can only partially divide the cermet body 101. Therefore, the volume ratio of the first segment 102 and at least one second segment 103 varies to produce optimal mass properties of the cermet body 101. In a preferred embodiment, the ratio of the volume of the first segment 102 to the volume of the second segment 103 is from about 0.25 to about 4, preferably from about 0.33 to about 2.0, and more preferably from about 0.4 to about 2 .

The method for producing the cermet body of the present invention is that a first powder mix and a second or at least one additional powder mix are provided, it will be apparent to those skilled in the art that a plurality of powder mixes may be provided. Each powder mix contains at least one ceramic component, at least one binder and at least one lubricant, i.e. an organic or inorganic material that facilitates solidification or aggregation of at least one ceramic component and at least one binder. The powder mix also optionally includes at least one surfactant. The preparation of each powder mix preferably includes, for example, milling with rods or a cycloid followed by mixing followed by drying in a spatula-sigma dryer or in a spray dryer. In each case, each powder mix is ​​prepared by means that are selected according to solidifying and / or thickening agents.

The first powder mix is ​​prepared from a pre-selected ceramic component, preferably at least one carbide, with a selected grain size or grain size distribution, and at least one second powder mix is ​​prepared from a finer ceramic component, preferably at least one carbide, of a given grain size or grain size distribution. The at least two powder mixtures are at least partially placed side by side, which ensures or facilitates the creation of novel metallic complexion bodies having at least two segments, having, after solidification and thickening by, for example, sintering, at least one different property.

The first powder mix contains a ceramic component, preferably at least one carbide, having a large grain size compared to at least one second powder mix. The grain sizes of the first powder mix are preferably in the range of from about submicron to about 420 microns or more, preferably, the grain sizes are in the range of from about submicron to about 30 microns or more, with the possibility of scattering grain size measurements generally in the order of about 40 microns. The sub-micrometer includes ultra-fine and nanostructured materials. Nanostructured materials have structural features ranging from about 1 nanometer to about 100 nanometers or more. Preferably, the grain size of the ceramic component of the first powder mix is ​​in the range of from about 0.5 microns to about 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns, while the average grain size preferably ranges from about 0 , 5 microns to about 12 microns, preferably, from about 3 microns to about 10 microns; and most preferably, from about 5 microns to about 8 microns.

The ceramic component of the first powder mix preferably contains at least one boride, at least one carbide, at least one nitride, at least one oxide, at least one silicide, solutions thereof, or any combination of the above. The metal of at least one boride, carbide, nitride, oxide, silicon contains at least one metal from groups 2, 3 (containing lanthanides and actinides), 4,5,6,7,8,9,10,11,12, l3 and 14 according to IUPAC. preferably,

178 269 ​​the ceramic component comprises at least one carbide, mixtures thereof, or any combination of the above. The carbide metal contains at least one metal from groups 3 (containing lanthanides and actinides), 4.5 and 6 according to IUPAC, more preferably a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, and most preferably tungsten.

The binder of the first powder mix preferably contains any material that is selected according to the manufacturing process and does not adversely affect the performance of the cermet body when used for it. Such materials include metals, ceramics, glasses, or any combination thereof, including mixtures, solutions, and alloys. Examples of metals suitable for use as binders include at least one metal from the IUPAC groups 8.9 and 10, preferably at least one metal selected from the group consisting of Fe, Co, Ni, mixtures thereof, their alloys and combinations thereof; and most preferably, cobalt or cobalt alloys such as tungsten cobalt alloys. The metal binder preferably includes mixtures of metal powders or an alloyed powder, or both.

The amount of binder in the first powder mix is ​​selected to adapt properties, for example, to provide sufficient wear resistance to the resulting first segment 102 of the cermet body 101 for its intended use. The binder content preferably ranges from about 2% to about 25% or more; preferably from about 5% to about 15%; and even more preferably, from about 9% to about · 10%.

The binder in the first powder mix has any size that facilitates shaping the cermet body of the present invention. A suitable average grain size is less than about 5 microns, preferably less than about 2.5 microns; and most preferably, less than about 1.8 microns.

One limitation for the second powder mix is ​​that the average grain size of the ceramic component is smaller than the average grain size of the ceramic component of the first powder mix. As for the first powder mix, the grain size of the ceramic component, preferably at least one carbide, is in the range of from about submicron to about 420 microns or more. The sub-micrometer includes ultra-fine and nanostructured materials. Nanostructured materials have structural features ranging from about 1 nanometer to about 100 nanometers or more. The preferred grain size is in the range of from about submicron to about 30 microns or more, with the possibility of scattering grain size measurements generally on the order of about 40 microns. Preferably, the grain size of the ceramic component of the second powder mix is ​​in the range of about one micrometer to about 30 micrometers or more, with the possibility of scattering grain size measurements generally on the order of about 40 micrometers. Unlike the first powder mix, the average grain size of the ceramic component of the second powder mix, preferably at least one carbide, and more preferably tungsten carbide, is in the range of from about 0.5 micrometer to about 8 micrometer, preferably from about 1 micrometer to about 5 microns, and more preferably, from about 2 to about 5 microns.

The ratio of the average grain size of the ceramic first powder mix and the average grain size of the second powder mix is ​​selected both to facilitate the shaping of the cermet body according to the present invention and to optimize the properties of the resulting cermet body. Thus, the ratio of average large grain size to average fine grain size is in the range of from about 1.5 to about 12, with a preferred ratio in the range of from about 1.5 to about 3.

The chemical composition of the ceramic component of the second or at least one additional powder mixture is substantially the same or substantially different from the chemical composition of the first powder mixture. Thus, the ceramic component of the second powder mix contains all of the aforementioned chemical components of the first powder mix.

Similarly, the chemical composition of the binder of the second powder mixture is substantially the same or substantially different from the chemical composition of the binder of the first powder mixture.

178 269

Talc, therefore, the binder of the second powder mix contains all of the listed chemical components of the binder of the first powder mix.

The binder content of each powder mix is ​​selected to facilitate the shaping of the cermet body and to ensure the optimal properties of the cermet body for its specific application. Thus, the content of the first binder in the powder mix is ​​greater, less than or substantially equal to the content of the binder in the second powder mix. Preferably, the binder content of the second powder mix varies in weight range from about zero (0) to about two (2) percentage points from the previously selected binder percentage in the first powder mix. In a more preferred embodiment, the binder content of the second powder mix is ​​less than the binder content of the second powder mix is ​​less than the binder content of the first powder mix. For example, if the previously selected binder content of the first powder mix is ​​about 9.5% by weight, then the binder content of the second powder mix ranges from about 7.5% to about 11.5%, preferably from about 9% to about 10 %, more preferably from about 7.5% to about 9.5%, and even more preferably from about 9% to about 9.5%.

The at least two powder mixtures are, at least partly, placed side by side by means of appropriate processes. Such processes preferably include, for example, casting, injection molding, extrusion, both simultaneous and sequential extrusion, belt casting, suspension casting, diecasting, sequential pressing, co-operation, or any combination of the above. Part of the methods for carrying out these processes is discussed in U.S. Patent Nos. 4,491,559; 4,249,955; 3,888,662; and 3,850,368, which are contained in this application by reference to them.

During the formation of the unbaked body, the at least two powder mixtures are preferably kept at least partially separated by the delivery assemblies either by separating or by both of them. Examples of delivery assemblies preferably include, for example, devices for implementing the method discussed above, and the separating assemblies preferably include a physically removed septum or a chemically removed septum, or both.

The physically removed barrier is preferably a paper barrier or other thin barrier that is placed in the matrix or mold when loading at least two powder mixtures, and which is removed from the matrix or mold after being filled with the powder mixture and before the powder mixture is compacted. More sophisticated physically removed partitions are preferably concentric or eccentric pipes (e.g., impermeable or permeable sheets, screens or metal or ceramic or polymeric mesh or of natural material or any combination of the above). The shapes of the physically removed partitions can be any, as long as they facilitate the separation of at least two powder mixtures.

A chemically removed barrier includes any barrier, straight and / or composite, permeable and / or impermeable, which is removed or absorbed by separated at least two powder mixtures by chemical processes. Such processes preferably include leaching or pyrolysis or the use of labile materials or alloying or any combination of the foregoing. Chemically removed partitions facilitate the formation of metallic complexion bodies according to the present invention in which at least two segments, both in cross section and in relation to the full geometry of the cermet body, have complex shapes.

In an embodiment of the present invention, the separated and at least partially side-by-side at least two powder mixtures are compacted by, for example, compression, including, for example, uniaxial, biaxial, triaxial, hydrostatic or wet, both at room temperature and at elevated temperature .

In any case, irrespective of whether they are concentrated or not, the full geometry of separated and at least partially placed side by side at least two cities

178 269 ​​powder cubes are preferably shaped from cubes, parallelepipeds, pyramids, truncated pyramids, cylinders, hollow cylinders, cones, truncated cones, or, sphere fragments, sphere sections, sphere sections, balls with cylindrical holes, balls with conical holes, torus, chamfered cylinders, oblique cones, barrels, prisms, ellipsoids and combinations thereof. In order to achieve a given shape, at least two powder mixtures separated and at least partially arranged side by side are preferably formed before or after compacting, or in both states. Recommended forming techniques include any of the above mentioned processes as well as the processing of the unbaked body or plastic deformation of the unbaked body or combinations thereof. Shaping after compaction involves comminution or any machining operations.

The outline of the cross-section of an uncooked solid is simple or complex, or a combination of both of them. Outline shapes include polygons, such as squares, rectangles, parallelograms, trapezoids, triangles, pentagons, hexagons, and the like, and circles, rings, ellipses, and the like.

The uncooked body containing the separated and at least partially arranged side by side at least two powder mixtures is then compacted by sintering the liquid phase. Compaction is carried out by any methods that are compatible with the production of the cermet body according to the present invention. Such methods include hot pressing, vacuum sintering, pressure sintering, hot isostatic pressing (HIP), and the like. These processes are carried out at a temperature and / or pressure sufficient to produce a theoretically substantially dense cermet body having minimal porosity. For example, for metallic complexions of tungsten carbide with cobalt, such temperatures include temperatures ranging from about 1300 ° C to about 165^p° C, preferably from about 1350 ° C to about 1537 ° C, and more preferably, from about 1500 ° C to about 1525 ° C. Compaction pressures range from about zero kPa to about 206850 kPa. For metallic cerium carbide bodies, pressure sintering is performed at a pressure of about 1723 kPa to about 13790 kPa, at temperatures from about 1370 ° C to about 1540 ° C, while HIP is performed at a pressure of about 58950 kPa to about 20 ( 5850 kPa at temperatures from about 1310 ° C to about 1430 ° C.

The compaction is carried out in a vacuum, under an inert atmosphere, e.g. in an atmosphere of at least one gas from Group 18 according to IUPAC, under a nitrogen atmosphere, e.g. nitrogen, forming gas (96% nitrogen, 4% hydrogen), ammonia, and the like, in a carburizing atmosphere or in a reducing gas mixture, for example H₂/ H₂O, CO / CO₂, CO / H₂/WHAT₂/ H₂Oh, and the like, or any combination of the above.

In the method of the invention, although without being limited to this particular theory or explanation of the present invention, it appears that although when the unbaked body is sintered in the liquid phase, the binder from the first powder mix passes through capillary wetting into the second powder mix or the ceramic component of the second powder mix is transferred by dissolution, diffusion, and precipitation into the first powder mix or both.

With regard to the capillary wandering mechanism, metallic binders, especially in cobalt-carbide systems, can easily wet the grains of the ceramic component. The grain size difference between the first powder mix and the second powder mix translates into the corresponding difference in effective capillary size of at least two powder mixes. The effective capillary size in the second powder mix (e.g., powder mix with fine grain size) would be smaller and thus provide the driving force for the molten binder to transition from the first powder mix to the second powder mix.

With regard to the dissolution, diffusion and precipitation mechanism, the difference in grain size of at least two powder mixtures translates into the corresponding difference in the effective surface area of ​​the two powder mixtures. The effective surface area of ​​the second powder mix (i.e. fine powder) would be larger and thus there would be a driving force reducing this area during compaction. As a result,

178 The finer grains would preferably dissolve in the molten binder, diffuse into the segment of the first powder mix, and precipitate on the coarser grains of the first powder mix.

The present invention is illustrated in the following Examples, which should not be construed as limiting the scope of the claimed invention.

Example 1

This example illustrates the production of a cermet body having a first segment and a second segment, wherein the first segment comprises a carbide material with a larger grain size and the second segment contains a carbide material with a small grain size. Placing the first segment and the second segment next to each other with a specific exterior or surface profile in a single cermet body facilitates its use for material removal, in particular for coal removal in mining operations. This example describes a method for producing a cerometallic body, the characteristics of ceemeSalicze body and a description of how to use a cermet body.

For the production of the cermet body according to the invention in Example 1, a granulated first powder mix and a granulated second powder mix were prepared separately. The first powder mix 314 (Figures 3A, 3B and 3C) contained, by weight, about 87.76% makeocrystalline tungsten carbide, about 9.84% very fine-grained cobalt binder, about 2.15% lubricating paraffin wax and about 0.25% surfactant.

Then a portion of the first powder mix was sintered, and the average tungsten carbide grain size, which had a known grain size ranging from about 1 micrometer to about 25 micrometers, with the possibility of measuring grain sizes generally about 40 micrometers, was determined by Equation ( 1) at about 6.7 microns, after measuring coercive (H_c) sintered metallic skin bodies and binder content (Χ ^) ·

The second powder mix 313 (Figures 3A, 3B and 3C) contained, by weight, about 88.82% tungsten makeoke-crystalline carbide, about 8.78% very fine-grained cobalt binder, about 2.15% lubricating paraffin wax and about 0.25% surfactant. The observed tungsten carbide grain size in the sintered portion was in the range of about 1 to about 9 microns, with the possibility of scattering grain size measurements generally in the order of about 40 microns, and the calculated average grain size determined by Equation (1) was about 2.8 micrometer.

The first powder mix 314 and the second powder mix 313 were then charged into a die cavity having a diameter of about 19 mm, using the charging device 301 schematically shown in Fig. 3A. The charging device 301 used includes a bottom slider 303 in contact with the inner side wall of the cylindrical matrix 302, connected to the outer portion 305 of the charging funnel 304, through the connecting portion 306 at the contact edge 307 between the outer part 305 of the charging funnel 304 and the cavity of the cylindrical matrix 302. The inner portion 308 of the charging funnel 304 contacts the top surface 312 of the bottom slide 303, forming the front surface of the ceemeSalic body, through the physically removable bottom part 310 of the loading funnel 304, which has a diameter of about 10 mm at the edge of contact 311 with the bottom slide 303.

About 8.4 grams of the first powder mix 314 was poured into the inner portion 308 of the charging funnel 304. About 18.6 grams of the second powder mix 313 was poured into the outer portion 305 of the charging funnel 304. After placing inside both the die cavity 302 of both the first powder mix 314 and the second powder mix 313, the inner parts 308 and outer 305 and bottom 310 of the charging funnel 304 were removed to form contact surface 317 between first powder mix 314 and second powder mix 313. The upper slider 315, having a front surface 316, forming the rear part of the solid ceramic body, was then moved, at approximately room temperature, to the first powder mix 314 and the second powder mix 313, at a load of about 31138N. After removing the load, the unbaked lumps 320 were pushed out of the cavity

178 269 ​​matrix 302 and had a front portion 321 formed by a bottom slider 303 and a rear portion formed by an upper slider 315. The uncooked body 320 contained the compacted first powder mix 314 and second powder mix 313. This operation was repeated until the right amount (about 72) of unbaked lumps was formed , comprising a first powder mix 314 and a second powder mix 313. In addition, several lumps containing only the first powder mix 314 and other lumps containing only the second powder mix 313 were formed. These lumps were used as control samples during sintering of the uncooked lumps 320 to determine the types of changes that may occur as a result of co-concentration of the first mix powder 314, contacting the second powder mix.

Once the right amount of unbaked lumps 320 were formed, the unbaked lumps 320 and control samples were placed in a pressure sintering furnace. The furnace was lowered to about 179.6 Pa, and then raised from approximately room temperature to about 177 ° C, at a rate of about 3.3 ° C per minute, in vacuo, and maintained at about 177 ° C for about 15 minutes , heated from about 177 ° C to about 371 ° C at a rate of about 3.3 ° C per minute, maintained at about 371 ° C for about 90 minutes, then heated from about 371 ° C to about 427 ° C at a rate of about 1.7 ° C (3 ° F) per minute, maintained a temperature of about 427 ° C for about 45 minutes, heated from about 427 ° C to about 538 ° C at about 1.4 ° C per minute; held at about 538 ° C for about 12 minutes, heated from about 538 ° C to about 593 ° C at a rate of about 1.4 ° C per minute, and then from about 593 ° C to about 1121 ° C at a rate of about 4, 4 ° C per minute, the temperature was maintained at about 11'21 ° C for about 30 minutes at a vacuum ranging from about 13 microns to about 29 microns, heated from about 1121 ° C to about 1288 ° C at a rate of about 4.4 ° C per minute, held at about 1288 ° C for about 30 minutes and then argon was introduced to a pressure of about 538.8 Pa. The furnace, in turn, was heated from about 1288 ° C to about 1510 ° C at a rate of about 3.3 ° C per minute, and argon was introduced to a pressure of about 5516 kPa, and then the temperature was kept at about 1510 ° C for about 5 minutes, followed by feeding the oven was turned off and the oven and its contents were allowed to cool to approximately room temperature at a rate of about 5.6 ° C per minute.

Several sintered metallic body bodies (now having a diameter of about 15.9 mm and included angle apex of about 75 °), containing sintered control samples for only the sintered first powder mix and only sintered second powder mix, have been characterized using metallography, chemical aerometric analysis, determination of magnetic properties and X-ray energy dissipation (EDS) analysis.

Table I presents the results of determining the properties of the first segment and the second segment of metallic complexions made according to this example and sintered control samples only from the first powder mix and only the second powder mix. The results of chemical aerometric analysis indicate that the cobalt binder passed from the first powder mix to the second powder mix during the compaction of the unbaked lump to form the cermet body. This transition of cobalt binder affects the hardness of the first segment relative to sintered control samples from only the first powder mix of the second segment relative to the cermet body sintered only the second powder mix. Fig. 4A is a photomicrograph, taken at about 3.4 times magnification, longitudinal section through a sintered cermet body 401 having a first segment 414 in contact with the second segment 413 at the boundary surface 417. The front portion 421 corresponds to the front portion of the uncooked body and the rear portion 422 corresponds to the portion of the rear uncooked body. Examination of the boundary surface 417 between the first segment 414 and at least one second segment 413 at about 500x magnification is shown in Figure 4B, while at about 1500x magnification in Figure 4E. Figures 4C and 4D are photomicrographs of the first segment 414

178 269 ​​and the second segment 413, taken at approximately 500x magnification, while FIG. 4F and 4G are photomicrographs of the first segment 414 and second segment 413, taken at approximately 1500x magnification. The first segment 414 and the second segment 413 are identical in Figures 4E, 4F and 4G and contain a binder in the form of a cobalt alloy 425, coarse tungsten carbide 426 and fine-grained tungsten carbide 427. The self-formed boundary surface 417 is clearly visible in Fig. 4E as a rapid change in tungsten carbide grain size. There is a self-produced metallic bond that is free of cracks and inclusions. These compact, sintered cermet bodies are also free of eta phase and C porosity.

TABLE I

<td colspan="10">RESULTS FOR DETERMINING THE PROPERTIES OF THE CERMETALIC BODY SEGMENTS</td>

<td></td><td colspan="9">PERFORMED ACCORDING TO EXAMPLE 1 AND AUDIT SAMPLES</td>

<td></td><td colspan="5">Chemical aerometric analysis results (% by weight) *</td><td>Hardness</td><td>Average calculation combined grain size</td><td>Coercion, H.</td><td>^ Saturation magnetic</td>

<td></td><td>What</td><td>this</td><td>ti</td><td>fe</td><td>Ni</td><td>Rockwell A.</td><td>Micron</td><td>Oersted'</td><td>Percent#</td>

<td colspan="10">THIS INVENTION</td>

<td>First</td><td> 5,45</td><td> 0,26</td><td> 0,16</td><td> 0,06</td><td> 0,02</td><td> 87,6</td><td> 7,8</td><td> 76</td><td> 92</td>

<td>segment</td><td> 5,48</td><td> 0,26</td><td> 0,16</td><td> 0,07</td><td> 0,02</td><td></td><td></td><td></td><td></td>

<td>Second</td><td> 10,75</td><td> 0,285</td><td> 0,17</td><td> 0,13</td><td> 0,02</td><td> 88,4</td><td> 2,8</td><td> 111</td><td> 91</td>

<td>segment</td><td> 10,78</td><td> 0,285</td><td> 0,17</td><td> 0,13</td><td> 0,02</td><td></td><td></td><td></td><td></td>

<td colspan="10">CONTROL SAMPLES</td>

<td>parched</td><td> 10,08</td><td> 0,28</td><td> 0,40</td><td> 0,10</td><td> 0,04</td><td> 86,1</td><td> 6,7</td><td> 51</td><td> 100</td>

<td>PMP *</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> 50</td><td> 100</td>

<td>parched</td><td> 9,00</td><td> 0,278</td><td> 0,15</td><td> 0,10</td><td> 0,02</td><td> 86,1</td><td> 2,8</td><td> 124</td><td> 91</td>

<td>DMP **</td><td> 9,01</td><td> 0,275</td><td> 0,16</td><td> 0,11</td><td> 0,02</td><td></td><td></td><td> 125</td><td> 92</td>

* PMP = first powder mix ** DMP = second powder mix during the test, the content of Nb, Cr and V was usually less than about 0.01% by weight. The material balance is W + C + other smaller admixtures # 100 percent = around 160 emu per gram or 1.7 tesla or 17,000 gauss! 1 ersted = 79.58 amps per meter (A / m) = 0.08 kiloamperes per meter (kA / m)

To determine the distribution of cobalt within the cermet body made by the method of this example 1, the mounted and polished sample was analyzed by means of non-standard drop analysis using X-ray energy dissipation (EDS) for two different cermet body diameters. Exactly, the scanning electron microscope JSM-6400 (model No. ISM64-3, JEOL LTD, Tokyo, Japan) equipped with the LaB cathode electron gun system was used₆ and an X-ray energy dissipation system with a silicon lithium sensor (Oxford Instrument Inc., Analytical System Division, Microanalysis Group, Bucks, England) with an acceleration potential of about 20 keV. The areas searched were about 125 micrometers by about 4 micrometers in size. Each area was searched for an equal period of time (about 50 seconds). The step size between adjacent areas was about 0.1 mm. FIG. 5 A and 5B show the results of these non-standard analyzes performed on the segment width. Fig. 5A corresponds to the results of the drip analysis carried out at a diameter of about 10.5 mm and shows a stepwise gradation of the cobalt content from the first segment (on average about 11.9% by weight) to the second segment (on average to about 7.2% by weight). Similarly, Fig. 5B shows the results of a drop22 analysis

178 269 ​​input for a diameter of about 15.5 mm and also suggests a stepwise gradation of the cobalt content from the first segment (on average about 12.3% by weight) to the second segment (on average about 7.6% by weight) of the cermet body. Figure 6 shows the results of the hardness profile of the cermet body, which shows that the hardness of the first segment (inner or core part of this cermet body) of Rockwell A 87.4-87.8 is less than the hardness of the second segment (outer or peripheral part of the present of the cermet corpus), which is Rockwell A »88.3-88.7.

Figure 7 shows a cutting tool 701 according to the invention comprising sintered cermet bodies made according to the present example 1, which are soldered to a steel body. Soldering of metallic complexion bodies is made using the materials disclosed in U.S. Patent No. 5,324,098, titled "Cutting tool having protrusion tip." The 701 cutting tool consists of an elongated 705 holder with an attached 702 hard tip. Mount 705 has a front end 710 and a rear end 707. Between the front 710 and rear 707 ends there is a portion with increased diameter 711 and a portion with reduced diameter 706 separated by a radially protruding flange 704. The front end 710 has a socket 709 for receiving a cutting tip 702. The cutting tip 702 consists of a first segment 714 and a second segment 715, at least partially self-metallic on the boundary surface 717. Tip 702 is connected to the housing 705 through attachment elements 703. Attachment elements 703 preferably include a solder layer, or a shrink fit zone, interference fit and their combination. The cutting tool 701 preferably includes the retaining elements shown in Fig. 7 preferably in the form of a retaining sleeve 708.

The 701 cutting tool was used to mine coal. In particular, coal having a compressive strength or hardness of about 12 MPa was mined at a height of about 3 meters on a given section using earlier tools made of coarse carbide carbide alloy (see sample 10 in Table V), and tools containing cermet bodies made according to this example 1. After 4 meters, 8 meters and 12 meters of mining, a change in the length of cutting tools containing prior cermetallic bodies and cutting tools containing cermetic bodies made according to the present invention was determined. The tip angle of some tools was also measured. The results determined after 4 meters, 8 meters and 12 meters for different positions are collected in Tables Π, III and IV, respectively. In particular, Tables II, III and IV show the position of the cutting tool, the change in length for a cutting tool containing prior cermetallic bodies and the tool containing cermetic bodies according to the present invention, the ratio of the length change, the apex angle values ​​for the known cutting tool, the apex angles for the cutting tool according to the present invention and the ratio of the apex angle change for the known tool to changing the apex angle of the cutting tool according to the present invention. It should be noted that the apex angle for all tools was initially 75 °.

TABLE II

<td colspan="7">CHARACTERISTIC CHARACTERISTICS OF THE TOOL AFTER FOLLOWING BY FOUR METERS</td>

<td rowspan="2">Position#</td><td colspan="3">length changes (mm)</td><td colspan="3">included angle (degrees)</td>

<td>solutions earlier</td><td>present invention</td><td>ratio</td><td>solutions earlier</td><td>present invention</td><td>ratio*</td>

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td>

<td> 1</td><td> 1,91</td><td> 0,84</td><td> 2,3:1</td><td> 89</td><td> 80</td><td> 2,8:1</td>

<td> 2</td><td> 0,71</td><td> 0,82</td><td> 0,9:1</td><td> 80</td><td> 80</td><td> 1,0:1</td>

<td> 3</td><td> 0,99</td><td> 0,99</td><td> 1,0:1</td><td> 81</td><td> 80</td><td> 2,1:1</td>

178 269

<td colspan="7">Table II (continued)</td>

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td>

<td> 4</td><td> 1,93</td><td> 1,27</td><td> 1,5:1</td><td> 91</td><td> 83</td><td> 2,0:1</td>

<td> 5</td><td> 2,72</td><td> 0,89</td><td> 3,1:1</td><td> 96</td><td> 80</td><td> 4,2:1</td>

<td> 6</td><td> 1,55</td><td> 1,12</td><td> 1,4:1</td><td> 88</td><td> 80</td><td> 2,6:1</td>

<td>medium</td><td> 1,63</td><td> 0,99</td><td> 1,6:1</td><td> 88</td><td> 81</td><td> 2,2:1</td>

TABLE III

<td colspan="7">CHARACTERISTIC CHARACTERISTICS OF THE TOOL AFTER MACHINING THROUGH EIGHT METERS</td>

<td rowspan="2">Position#</td><td colspan="3">length changes (mm)</td><td colspan="3">included angle (degrees)</td>

<td>solutions earlier</td><td>present invention</td><td>ratio</td><td>solutions earlier</td><td>present invention</td><td>ratio*</td>

<td> 1</td><td> 2,29</td><td> 0,56</td><td> 4,0:1</td><td> 92</td><td> 80</td><td> 3,4:1</td>

<td> 2</td><td> 1,75</td><td> 2,26</td><td> 0,8:1</td><td> 90</td><td> 87</td><td> 1,3:1</td>

<td> 5</td><td> 2,13</td><td> 1,35</td><td> 1,6:1</td><td> 94</td><td> 83</td><td> 2,4:1</td>

<td> 6</td><td> 2,36</td><td> 1,50</td><td> 1,6:1</td><td> 96</td><td> 85</td><td> 2,1:1</td>

<td>medium</td><td> 2,33</td><td> 1,40</td><td> 1,5:1</td><td> 93</td><td> 84</td><td> 2,0:1</td>

TABLE IV

<td colspan="7">CHARACTERISTIC CHARACTERISTICS OF THE TOOL AFTER FOLLOWING BY TWELVE METERS</td>

<td rowspan="2">Position#</td><td colspan="3">length changes (mm)</td><td colspan="3">included angle (degrees)</td>

<td>solutions earlier</td><td>present invention</td><td>ratio</td><td>solutions earlier</td><td>present invention</td><td>ratio*</td>

<td> 2</td><td> 3,07</td><td> 1,09</td><td> 2,8:1</td><td> 97</td><td> 81</td><td> 3,7:1</td>

<td> 3</td><td> 0,97</td><td> 1,68</td><td> 0,6:1</td><td> 83</td><td> 78</td><td> 2,7:1</td>

<td> 4</td><td> 1,93</td><td> 2,49</td><td> 0,8:1</td><td> 86</td><td> 82</td><td> 1,6:1</td>

<td> 6</td><td> 2,36</td><td> 0,30</td><td> 0,8:1</td><td> 91</td><td> 93</td><td> 0,9:1</td>

<td>medium</td><td> 2,08</td><td> 2,06</td><td> 1,0:1</td><td> 89</td><td> 84</td><td> 1,6:1</td>

* Change in the included angle according to the present invention: change in the included angle according to earlier solutions # Data for positions 3 and 4 in Table III and 1 and 5 in Table IV cannot be given, because both the tools of the present invention and earlier solutions have failed, for example, by a soldering defect or damage to the tool.

To graphically illustrate the various aspects of the present invention, Figures 8 and 9 show a comparison of the measurement of tip profiles of the cutting tools of the present invention (solid line), endings according to earlier solutions (dashed line), and the initial end profile (dotted line) as a function of position in cutting tool for positions 1.3 and 5 after 4 meters of mining, and positions 1.5 and 6 after 8 meters of mining. The data for Tables II, III and IV and the comparisons shown in Figures 8 and 9 show that cermet bodies made according to the present invention show better abrasion resistance, while substantially maintaining their original profiles. Thus, the present invention provides a method

178 269 ​​manufacture of metallic complexion bodies showing better properties for applications including material removal.

Example 2

In Example 2, the same procedure as in Example 1 was used to shape sintered cermet bodies having a diameter of about 17.5 mm, with the difference that in example 2 the total mass of the unbaked lump was about 47 grams, not 27 grams, and the diameter the unbaked lump was about 21 mm. In addition, the consolidation load used to shape the uncured bodies in Example 2 was about 37365 N, not 31138 N.

As in Example 1, for comparison control samples were made containing only the first powder mix or only the second powder mix. The resulting cermet bodies were characterized in a similar manner to that of Example 1. Table V compares the weight percentages of the first powder mix and the second powder mix, which have been combined to shape unbaked lumps and ultimately compacted metallic body bodies, zone size of the first powder mix, results of chemical aerometric analysis, hardness measurements, and magnetic properties measurements. Thus, Example 2 shows a method for adapting the binder content of the first segment and the second segment for a cermet body made using the methods of the present invention. The results show that the entire quantity range of the first powder mix is ​​combined with at least one additional powder mix when forming the cermet bodies of the present invention.

The cermet composite bodies according to the invention can be used for material manipulation or removal, including, for example, mining, construction, agricultural and metal removal applications. Some examples of agricultural applications include seed boxes, inserts for agricultural tools, disc blades, grubbers or grinders, cutting tools, and soil preparation tools. Some examples of mining and construction applications include cutting or digging tools, earth drills, mineral or rock drills, construction equipment blades, rolling knives, soil working tools, crushing devices, digging tools and other mining and construction tools. Some examples of material removal applications include cutting inserts or milling materials, cutting inserts or milling materials containing chip rolling elements, and cutting inserts or milling materials containing coatings applied by any gas phase chemical planting (CVD), gas phase pressure deposition (PVD) ), conversion coating, and so on. The cermet composite body products of the invention can be used especially in abrasive applications where the product includes, for example, a previously selected geometry with a leading edge that processes or removes materials (e.g. rock, wood, ore, coal, soil, road surface, synthetic materials) , metals, alloys, composite materials (ceramic matrix composites (CMC), metallic matrix composites (MMc), and polymer matrix composites or plastics (PMC) composites, polymers, etc.). More specifically, articles can be used in applications where it is desirable to substantially maintain the previously selected geometry during the lifetime of the article.

178 269 •3

TABLE V

<td>satura- no magnetic tic</td><td>percent"</td><td> 91</td><td> 94</td><td>d</td><td> 92</td><td> 1</td><td> 1</td><td>d</td><td>04 d</td><td>d</td><td> 94</td><td>d d</td><td> 89</td>

<td>coercion, hc</td><td>oersted'</td><td>11 and "4</td><td> 79</td><td> 04 0·*</td><td> 76</td><td>AND</td><td> 1</td><td></td><td> 76</td><td> 109</td><td>tt C</td><td> 57</td><td> 125</td>

<td>hardness 1</td><td>Rockwell AND</td><td> 88,6</td><td> 87,8</td><td> 88,4</td><td> 87,7</td><td></td><td> 1</td><td> 88,4</td><td> 87,6</td><td> 88,3</td><td> 87,6</td><td>0 "4 SO * 00</td><td>d * 00</td>

<td>average calculated size grains</td><td>micron _1</td><td> 2,91</td><td>ABOUT</td><td> 2,92</td><td> 7,07</td><td> 1</td><td>t</td><td> 2,90</td><td> 98*9</td><td> 2,90</td><td> 6,93</td><td>0H ol about*</td><td>ol °° 0 of</td>

<td rowspan="7"> ' ¹¹ ' ¹ III- · - 1 .......... .1 ......... 1 | chemical aerometric analysis results (% by weight)</td><td>cr 1</td><td> 0,01 0,01</td><td> 0,02 0,01</td><td>IO'O I0'0</td><td> &lt;0,01 0,01</td><td> &lt;0,01</td><td> 04 04 © ©_and©* ©*</td><td> &lt;0,01</td><td>ł— &lt;Ol © © © * © Γ</td><td> 0,01 0,02</td><td>&lt;0.0 and</td><td>rH © © * V</td><td> &lt;0,01</td>

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<td>H</td><td>00 00 o * o *</td><td> 0,15 0,15</td><td> 0,17 0,17</td><td>»2« 2 0 »4 T“ 4 O * ©</td><td>d 00 0-t 0 «d © * ©</td><td>3 3) 0H 0-4 ABOUT &amp;</td><td> 0,17 0,17</td><td>3 3 0 ^ 04 O * o *</td><td>oo d rt 04 O * © *</td><td>3 3 © * O *</td><td>0D \ o o * © *</td><td>about- - «- 4 © * o *</td>

<td>this</td><td>r- oo 04 04 o * o *</td><td>m &lt;2 04 04 ^ o * © *</td><td> 0,28 048 1</td><td> 0,23 0,22</td><td>d © 04 m</td><td> 0,23 0,23</td><td> 0,28 0,27</td><td>Tf τ ± · 04 04 © Γ © *</td><td> 0,29 0,29</td><td>&lt;2 (2 Ol Ol © *</td><td>3 Tt 04 Ol θ O *</td><td>N 00 04 04 cT © *</td>

<td>What</td><td>dd 00 ^ 00 ^ d * d *</td><td> 5,79 5,74</td><td> 10,14 10,09</td><td>5, 00 Ογ O \ 3 * 3?</td><td> 10,52 10,49</td><td>© 3 © ^ © ^ \ O kO</td><td> 10,41 10,41</td><td>O- 0 0 ^ 04 O \ o</td><td> 10,74 10,77</td><td> 6.33 6.34</td><td>3 \ O 3 ^ 3 ^ d * d *</td><td>31 \ O ©_Λd * d *</td>

<td>location inside samples</td><td>segmeni second 1</td><td>segment first</td><td>segmeni second</td><td>segment first</td><td>segmeni second</td><td>segment first</td><td>segmeni second</td><td>segment first</td><td>segmeni second</td><td>segment first</td><td> 1</td><td> 1</td>

<td rowspan="2">batch port</td><td>. * 00 CL D *</td><td> 78,7</td><td></td><td>about? about*</td><td></td><td> 68,9</td><td></td><td> 68,9</td><td></td><td> 64,0</td><td></td><td> ©</td><td> 100</td>

<td>. * * ε</td><td></td><td> 21. 04</td><td></td><td> 26,8</td><td></td><td></td><td></td><td>m</td><td></td><td> 36,0</td><td> © © 0“4</td><td> ©</td>

<td rowspan="2">PMP * zone dimensions</td><td>diameter mm</td><td colspan="2"> 00*</td><td colspan="2"> 9*8</td><td colspan="2">sO ^ WHAT</td><td colspan="2"> 00*</td><td colspan="2">d *</td><td> 1</td><td> 1</td>

<td>length mm</td><td colspan="2"> 15,5</td><td colspan="2">N * 0 · ^</td><td colspan="2"> 19,6</td><td colspan="2"> 19,6</td><td colspan="2"> 19,3</td><td> 1</td><td> 1</td>

<td></td><td>a sample No.</td><td colspan="2">c " 00</td><td colspan="2"> 74</td><td colspan="2">91 cs</td><td colspan="2"> 92</td><td colspan="2"> 82</td><td> ©</td><td>ol ol</td>

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UP Department of Publications. Circulation of 70 copies Price PLN 6.00.