Mitsubishi Materials Corporation

Mitsubishi Materials Kobe Tools Corporation

Yasuhiko Tashiro

Eiji Nakamura

Hidemitsu Takaoka

Toshiaki Ueda

Yusuke Tanaka

Akihiro Kondo

Kazunori Sato

Koki Okada

Takatoshi Ohshika

The invention provides a coated cutting tool made of cemented carbide in which a hard coating layer has excellent wear resistance in high-speed cutting operation, wherein (a) a crystal orientation hysteresis layer which consists of a carbonitride compound layer and (b) a hard coating layer which consists of a layer of nitride compound and has a well defined crystal orientation and/or degree of crystallinity are formed on the surface of a cemented carbide substrate, preferably on the surface of a tungsten carbide based cemented carbide or titanium carbonitride based cermet by physical vapor deposition, wherein the crystal orientation hysteresis layer is deposited between the surface of a cemented carbide substrate and the hard coating layer. In one specific example, (a1) the carbonitride compound layer has an average thickness of 0.05 to 0.5 &#x3bc;m and is preferably a Ti&#x2014;Al carbonitride compound layer expressed by the composition formula as (TiAl)(NC), wherein X ranges from 0.05 to 0.20 and Y ranges from 0.01 to 0.15 by atomic ratio and (b1) the nitride compound layer has an average thickness of 2 to 15 &#x3bc;m and is preferably a Ti&#x2014;Al nitride compound layer expressed by the composition formula as (TiAl)N, wherein Z ranges from 0.45 to 0.65 by atomic ratio. In another specific example, (a2) the carbonitride compound layer has an average thickness of 0.05 to 0.5 &#x3bc;m and is preferably a Ti&#x2014;Al carbonitride compound layer expressed by the composition formula as (TiAl)(NC), wherein X ranges from 0.01 to 0.15 and Y ranges from 0.01 to 0.15 by atomic ratio and (b2) the nitride compound layer has an average thickness of 2 to 10 &#x3bc;m and is preferably a Al&#x2014;Ti&#x2014;Si nitride compound layer expressed by the composition formula as (AlTiSi)N, wherein A ranges from 0.35 to 0.55 and B ranges from 0.05 to 0.20 by atomic ratio.

Surface coated cemented carbide cutting tool having hard coating layer exhibiting excellent wear resistance in high speed machining

A surface-coated cutting tool member exhibiting a superior tool life due to a hard coating layer thereof is provided. The surface-coated cutting tool member includes a tungsten carbide based cemented carbide substrate, a titanium carbonitride based cermet substrate, or a cubic boron nitride based sintered substrate; and a hard coating layer of a nitride compound containing titanium and yttrium, which is formed on a surface of the substrate using a physical vapor deposition method in an overall average thickness of 1 to 15 &#x3bc;m. The hard coating layer has a component concentration profile in which maximum Y component containing points (minimum Ti component containing points) and points without Y component (TiN points) appear alternatingly and repeatedly at a predetermined interval in a direction of thickness of the hard coating layer, and the amount of contained Y component is continuously changed from the maximum Y component containing points to the points without Y component and from the points without Y component to the maximum Y component containing points, the maximum Y component containing points satisfy a composition formula of (TiY)N (where X indicates an atomic ratio of 0.005 to 0.15), and a distance between one of the maximum Y component containing points and adjacent one of the points without Y component is from 0.01 to 0.1 &#x3bc;m.

Surface-coated cutting tool member having hard coating layer and method for forming the hard coating layer on surface of cutting tool

A cutting tool has a surface-coated carbide alloy and a wear-resistant coating layer which has excellent adhesion and chipping resistance. The cutting tool has a surface-coated carbide alloy comprising: a tungsten carbide-based carbide alloy substrate having an amorphous layer formed by an arc ion plating surface treatment to an average depth of 1 to 50 nm from the surface; and a wear-resistant coating layer deposited physically and/or chemically on the surface of the tungsten carbide-based carbide alloy substrate, the wear-resistant coating layer comprising: (a) a lower tough layer made of a titanium nitride layer and having an average thickness of 0.1 to 5 &#x3bc;m; and a single-layered or multi-layered surface hard layer which is made of a composite nitride layer of Ti and Al and a composite carbonitride layer of Ti and Al, which respectively satisfy the composition formula: (TiAl)N and the composition formula: (TiAl)CN(wherein X represents 0.15 to 0.65 and Y represents 0.5 to 0.99 in terms of an atomic ratio), and has an average thickness of 0.5 to 15 &#x3bc;m.

Surface-coated carbide alloy tool

A coated cutting tool has high wear resistance in a high-speed cutting operation of steel. The tool is made of a hard sintered substrate and has a hard coating layer deposited on a surface of the substrate. This hard coating layer includes a hard material layer and an inner layer having 0.1 to 10 &mgr;m for an average thickness with residual compressive stress. The inner layer is applied by physical vapor deposition. The hard coating layer also has an aluminum oxide layer as an outer layer having 0.1 to 5 &mgr;m for an average thickness. This outer layer is applied by chemical vapor deposition at a middle temperature.

Growing community of inventors

Tsukuba, Japan

Yasuhiko Tashiro