Surface-coated cutting tool having hard coating layer that exhibits excellent chipping resistance
AssigneeMitsubishi Materials Corporation
InventorsSho Tatsuoka, Kenji Yamaguchi
Life of this patent
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Abstract
The hard coating layer includes at least a complex nitride or complex carbonitride layer expressed by the composition formula (Ti1-xAlx)(CyN1-y). The average Al content ratio xavg the average C content ratio yavg satisfy 0.60≤xavg≤0.95 and 0≤yavg≤0.005, respectively, each of the xavg and yavg is in atomic ratio. The crystal grains constituting the complex nitride or complex carbonitride layer include a crystal grain having the NaCl face-centered cubic structure. A predetermined average crystal grain misorientation exists in the crystal grains having the NaCl face-centered cubic structure.
Claims9
A surface-coated cutting tool comprising:
- a tool body made of cemented carbide using tungsten carbide, titanium carbonitride cermet, or cubic boron nitride ultra-high pressure sintered material;
- and
- a hard coating layer provided on a surface of the tool body, wherein (a) the hard coating layer comprises at least a Ti and Al complex nitride or complex carbonitride layer, which is deposited by a chemical vapor deposition method and has an average layer thickness of 1 μm to 20 μm;
- and an average content ratio xavg, which is an average content ratio of Al with respect to a total amount of Ti and Al in the Ti and Al complex nitride or complex carbonitride layer, and an average content ratio yavg, which is an average content ratio of C with respect to a total amount of C and N in the Ti and Al complex nitride or complex carbonitride layer, satisfy 0.60≤xavg≤0.95;
- and 0≤yavg≤0.005, respectively, in a case where a composition formula of the Ti and Al complex nitride or complex carbonitride layer is expressed by (Ti1-xAlx)(CyNi1-y), each of the xavg and yavg is in atomic ratio,
- (b) the complex nitride or complex carbonitride layer comprises at least a phase of Ti and Al complex nitride or complex carbonitride having a NaCl face-centered cubic structure, and
- (c) an area ratio of crystal grains having an average crystal grain misorientation of 2° or more relative to the Ti and Al complex nitride or complex carbonitride layer is 40% or more, when crystal orientations of crystal grains of Ti and Al complex nitride or complex carbonitride having the NaCl face-centered cubic structure are analyzed along a vertical cross-sectional direction with an electron beam backscattering analyzer and the average crystal grain misorientation of the crystal grains is obtained.
Dependencies are inferred from the claim text.