Nova Patents
CA2552445C

Hard film for cutting tools, cutting tool coated with hard film, process for forming hard film, and target used to form hard film

Abstract

A hard film for cutting tools which is composed of (Ti1-a-b-c-d, Al a, Cr b, Si c, B d) (C l-e N e) 0.5 <= a <= 0.8, 0.06 <= b, 0 <<= c <= 0.1, 0 <= d <= 0.1, 0 <= c+d <= 0.1, a+b+c+d < 1, 0.5 <= e <= 1 (where a, b, c, and d denote respectively the atomic ratios of Al, Cr, Si, and B, and a denotes the atomic ratio of N).

CA2552445C, drawing sheet 1
Sheet 1 of 7

Term

Term ended

Expired 24 December 2021, 4.8 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

12 claims: 10 independent, 2 dependent

  1. 1
    CA 02552445 2009-06-09 CLAIMS :1. A hard film for cutting tools which is composed of (Tii-a-b, Ala, Crfc) (Ci_eNe) 0.55 < a < 0.8, 0.06 < b < 0.20, a+b <1, 0 < e <1 (wherein a and b denote respectively the atomic ratios of Al, and Cr, and e denotes the atomic ratio N).
  2. 2
    The hard film for cutting tools as defined in Claim 1, wherein the values of a and b in the range of 0.02 < 1-a-b < 0.20, 0.65 < a < 0.765, 0.06 < b < 0.20, or 0.02 < 1-a-b < 0.175, 0.765 < a, 4(a-0.75) < b < 0.20.
  3. 4
    The hard film for cutting tools as defined in any one of Claims 1 to 3 which has a crystal structure which substantially comprises a sodium chloride structure.
  4. 5
    The hard film for cutting tools as defined in Claim 4, wherein the sodium chloride structure is one which has the (111) plane, (200) plane, and (220) plane such that the intensity of diffracted rays from them measured by X-ray diffraction (Θ-2Θ method), which is denoted by 1(111), 1(200), and 1(220), respectively, satisfies expression (1) and/or expression (2) and expression (3) given below. 1(220) < 1(111)....................................(1) I (220) < I (200)....................................(2) I (200) /1(111) > 0.1........................(3) CA 02552445 2009-06-09
  5. 7
    The hard film for cutting tools as defined in Claim 6, wherein the diffracted ray from the (111) plane has a half width not larger than 1°.
  6. 8
    A process of forming hard film on cutting tools defined in any one of Claims 1 to 7, said process comprising vaporizing and ionizing a metal in a film-forming gas atmosphere and accelerating the conversion of said metal and film-forming gas into a plasma, wherein the vaporization and ionization of the target metal are accomplished by the arc ion plating method that employs arc discharging and the conversion of film-forming gas into plasma is accelerated in the vicinity of the substrate by magnetic lines of force, thereby forming the film.
  7. 9
    The process of forming hard film on cutting tools as defined in Claim 8, wherein the magnetic lines of force:a) are parallel to the normal at the target's evaporating surface, and b) run toward the substrate in the direction parallel to or substantially perpendicular to the target's evaporating surface.
  8. 10
    The process of forming hard film on cutting tools defined in Claim 9, wherein a bias voltage to be applied to the substrate is -50V to -400V with respect to earth potential. CA 02552445 2009-06-09
  9. 11
    The process of forming hard film on cutting tools defined in Claim 9 or 10, wherein the temperature of the substrate is kept at 300-800°C at the time of film forming.
  10. 12
    The process of forming hard film on cutting tools defined in any one of Claims 9 to 11, wherein the reactant gas for film forming has a partial pressure or total pressure in the range of 0.5 to 7 Pa.
Independent claims10