Surface-coated cutting tool in which hard coating layer exhibits exceptional welding resistance, plastic deformation resistance, and anomalous damage resistance

Patent metadata

Field	Value
Publication number	US-11623893-B2
Application number	US-201917283744-A
Country	US
Kind code	B2
Filing date	Oct 11, 2019
Priority date	Oct 11, 2018
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A surface-coated cutting tool according to the present invention includes a tool body and a hard coating layer including a complex carbonitride layer containing a small amount of chlorine and (Ti (1-x) Zr xy Hf x(1-y) )(N (1-z) C z ) (0.10≤x≤0.90, 0<y≤1.0, 0.08<z<0.60), a ZrHf and C content ratios in cycles, a cycle distance between a maximum ZrHf content point and an adjacent minimum ZrHf content point and a cycle distance between a maximum C content point and an adjacent minimum C content point are 5 to 100 nm, an average value of content ratio differences Δx and Δz is 0.02 or more, a distance between the maximum ZrHf content point and the maximum C content point is ⅕ or less of the distance between a maximum content point and a minimum content point of adjacent ZrHf components, and a composition fluctuation structure is 10% or more.

First claim

What is claimed is:

1. A surface-coated cutting tool comprising:
a tool body; and
a hard coating layer formed on a surface of the tool body, wherein
(a) the hard coating layer includes at least one layer of a TiZr complex carbonitride layer or a TiZrHf complex carbonitride layer having an average layer thickness of 0.5 to 20.0 μm,
(b) the complex carbonitride layer contains TiZr complex carbonitride or TiZrHf complex carbonitride, and in a case where the complex carbonitride is represented by a composition formula (Ti (1-x) Zr xy Hf x(1-y) )(N (1-z) C z ),
the complex carbonitride layer has an average composition in which a content ratio x of a total content of Zr and Hf to a total content of Ti, Zr, and Hf, a content ratio y of a Zr content to the total content of Zr and Hf, and a content ratio z of a C content to a total content of N and C (here, all of x, y, and z are atomic ratios) satisfy 0.10≤x≤0.90, 0<y≤1.0, and 0.08<z<0.60, respectively,
the complex carbonitride layer contains chlorine in an average chlorine content of 0.001 atom % or more and 0.030 atom % or less,
(c) the complex carbonitride layer has a composition fluctuation structure in which the content ratio of the total content of Zr and Hf to the total content of Ti, Zr, and Hf and the content ratio of the C content to the total content of N and C change in cycles in at least some crystal grains,
(c-1) in longitudinal cross section observation, an area ratio of the composition fluctuation structure occupying a structure of the complex carbonitride layer is 10% or more,
(c-2) regarding the content ratio of the total content of Zr and Hf to the total content of Ti, Zr, and Hf in the composition fluctuation structure, a maximum ZrHf content point showing a maximum content ratio x max and a minimum ZrHf content point showing a minimum content ratio x min are repeated, an average distance which is an average value of distances between the repeated maximum ZrHf content point and the minimum ZrHf content point adjacent to each other is 5 to 71 nm, and an average value of absolute values of differences Δx between the maximum content ratio x max of the maximum ZrHf content point and the minimum content ratio x min of the minimum ZrHf content point is 0.06 to 0.32,
(c-3) regarding the content ratio of the C content to the total content of N and C in the composition fluctuation structure, a maximum C content point showing a maximum content ratio z max and a minimum C content point showing a minimum content ratio z min are repeated, an average distance which is an average value of distances between the repeated maximum C content point and the minimum C content point adjacent to each other is 5 to 71 nm, and an average value of absolute values of differences Δz between the maximum content ratio z max of the maximum C content point and the minimum C content ratio z min is 0.02 or more, and
(c-4) cycles and positions of the maximum ZrHf content point showing the maximum content ratio x max and the minimum ZrHf content point showing the minimum content ratio x min , regarding the content ratio of the total content of Zr and Hf to the total content of the Ti, Zr, and Hf in the composition fluctuation structure, are respectively synchronized with cycles and positions of the maximum C content point showing the maximum content ratio z max and the minimum C content point showing the minimum content ratio z min , regarding the content ratio of the C content to the total content of N and C, and an average value of a distance between the maximum ZrHf content point and the maximum C content point at a position closest to the maximum ZrHf content point is ⅕ or less of the average distance between the maximum ZrHf content point and the adjacent minimum ZrHf content point.

2. The surface-coated cutting tool according to claim 1 ,
wherein the composition fluctuation structure is a laminated structure.

Assignees

• Mitsubishi Materials Corp

Inventors

• Murakami Akihiro
• Okude Masaki
• Nishida Shin

Classifications

• C23C16/36 Primary

  Carbonitrides · CPC title

• C04B35/58021 Primary

  based on titanium carbonitrides · CPC title

• C04B35/62218

  obtaining ceramic films, e.g. by using temporary supports · CPC title

• C04B41/87

  Ceramics · CPC title

• C04B35/62222

  obtaining ceramic coatings (coating of mortars, concrete, artificial or natural stone or ceramics C04B41/45; laminated ceramic products B32B18/00; coating of glass C03C17/00, applying ceramic coatings on silicon for semi-conductor purposes H10W; coating metallic materials C23) · CPC title