Mitsubishi Materials Corporation

Mitsubishi Materials Kobe Tools Corporation

Mmc Kobelco Tool Co., Ltd.

Natsuki Ichimiya

Koichi Maeda

Tsuyoshi Ogami

Tatsuo Hashimoto

Yusuke Tanaka

Yasuyuki Yamada

Kazuaki Tanaka

Yuki Matsuoka

Masanori Morikawa

Kenji Yamamoto

Toshiki Sato

Shun Sato

Tatsuya Yasunaga

Taiitsu Aoki

Seiichiro Kitaura

Genki Matsumoto

Koichi Tanaka

Yasutaka Okazaki

At least a (AlCrSiCu)N (where 0.15&#x2264;a&#x2264;0.40, 0.05&#x2264;b&#x2264;0.20, and 0.005&#x2264;c&#x2264;0.05) layer is provided on a surface of a tool body, a Cr concentration or a Cu concentration periodically changes in a layer thickness direction, a concentration Crmax in a highest content point of Cr is in a range of a&#x3c;Crmax&#x2264;1.3a, a concentration Crmin in a lowest content point of Cr is in a range of 0.50a&#x2264;Crmin&#x3c;a, and optionally in a case where a Cu composition at one point z along the layer thickness direction is represented by cand a Cr composition at the point z is represented by a, (c/a)/(c/a) is 0.7 to 1.5 over the layer thickness direction entirely.

Surface-coated cutting tool

Provided is a surface-coated cutting tool including: a cutting tool body and a hard coating layer on a surface of the cutting tool body, wherein the hard coating layer includes a complex nitride layer of Al, Cr, Si, and Cu, the complex nitride layer of Al, Cr, Si, and Cu includes a main phase, and CrSi-rich particles and Al-rich particles that are dispersed in the main phase, the main phase satisfies 0.15&#x2264;&#x3b1;&#x2264;0.40, 0.05&#x2264;&#x3b2;&#x2264;0.20, 0.005&#x2264;&#x3b3;&#x2264;0.05, and 0.45&#x2264;x&#x2264;0.60, the CrSi-rich particles satisfy 0.20&#x2264;&#x3b1;&#x2264;0.55, 0.20&#x2264;&#x3b2;&#x2264;0.55, 0&#x2264;&#x3b3;&#x2264;0.10, and 0.02&#x2264;x&#x2264;0.35, the Al-rich particles satisfy 0.10&#x2264;&#x3b1;&#x2264;0.25, 0.05&#x2264;&#x3b2;&#x2264;0.25, 0&#x2264;&#x3b3;&#x2264;0.10, and 0.02&#x2264;x&#x2264;0.35 in a composition formula: (AlCrSiCu)N), and an occupancy area ratio of the CrSi-rich particles having a major axis of 100 nm or more is 0.20 to 2.0 area %; and an occupancy area ratio of the Al-rich particles having a major axis of 100 nm or more is 0.50 to 3.0 area %.

Surface-coated cutting tool having excellent chipping resistance and wear resistance

A surface-coated cutting tool includes a tool body and a hard coating layer including a lower layer and an upper layer. The lower layer is made of a complex nitride layer of Al, Ti, and Si with the thickness of 0.3 to 3.0 &#x3bc;m. It satisfies 0.3&#x2264;&#x3b1;&#x2264;0.5 and 0.01&#x2264;&#x3b2;&#x2264;0.10 (atomic ratio) being expressed by (AlTiSi)N. The upper layer is made of a complex nitride layer of Al, Cr, Si, and Cu with the thickness of 0.5 to 5.0 &#x3bc;m. It satisfies 0.15&#x2264;a&#x2264;0.40, 0.05&#x2264;b&#x2264;0.20, and 0.005&#x2264;c&#x2264;0.05 (atomic ratio) being expressed by (AlCrSiCu)N. The upper layer is made of crystals having a hexagonal structure, and a half width of a diffraction peak of a (110) plane present in a range of 2&#x3b8;=55&#xb0; to 65&#xb0; is 1.0&#xb0; to 3.5&#xb0;.

A surface-coated cutting tool includes: a tool body made of any one of tungsten carbide-based cemented carbide, TiCN-based cermet, a cubic boron nitride sintered material, and high-speed tool steel; and a hard coating layer provided on a surface of the tool body. The hard coating layer includes at least a complex nitride layer of Al, Cr, Si, and Cu with an average layer thickness of 0.5 to 8.0 &#x3bc;m. The complex nitride layer of (AlCrSiCu)N satisfies 0.15&#x2264;a&#x2264;0.40, 0.05&#x2264;b&#x2264;0.20, and 0.005&#x2264;c&#x2264;0.05 (here, each of a, b, and c is in atomic ratio). The complex nitride layer has a hexagonal crystal structure. A half width of a diffraction peak of a (110) plane present in a range of 2&#x3b8;=55&#xb0; to 65&#xb0; by performing X-ray diffraction on the complex nitride layer is 1.0&#xb0; to 3.5&#xb0;.

This invention provides a surface-coated cutting tool which exhibits excellent fracture resistance and wear resistance in high-speed cutting, such as high-speed gear cutting, high-speed milling, and high-speed drilling. The surface-coated cutting tool includes a hard coating layer composed of an alternately laminated layer structure of at least a thin layer A and a thin layer B formed on the surface of a tool substrate, such as a cemented carbide substrate, a cermet substrate, and a high-speed tool steel substrate. The thin layer A is an (Al, Cr, Si)N layer which satisfies a compositional formula: [AlCrSi]N (0.2&#x2266;X&#x2266;0.45, 0.4&#x2266;Y&#x2266;0.75, 0.01&#x2266;Z&#x2266;0.2, and X+Y+Z=1 in terms of atomic ratio). The thin layer B is an (Al, Ti, Si)N layer which satisfies a compositional formula: [AlTiSi]N (0.05&#x2266;U&#x2266;0.75, 0.15&#x2266;V&#x2266;0.94, 0.01&#x2266;W&#x2266;0.1, and U+V+W=1 in terms of atomic ratio).

The invention provides a high-speed tool steel gear cutting tool in which fracture or chipping does not occur at the cutting edge, and which realizes excellent cutting performance over long periods. Moreover, a method of manufacturing a gear cutting tool including: a step for quenching a tool material comprising high-speed tool steel and which has been rough processed to a shape corresponding to a final shape of a gear cutting tool, to transform a structure of the tool material into martensite, a step for temperling the tool material after quenching to transform any residual austenite dispersingly distributed throughout a matrix of the martensite structure formed by the quenching, into martensite, and a step for finishing the tool material after tempering to a final shape, is characterized in that the tool material after quenching is subjected to sub-zero treatment involving cooling and holding at a temperature of less than &#x2212;150 &#xb0; C.

Manufacturing method for high-speed tool steel gear cutting tool

The invention provides a high-speed tool steel gear cutting tool in which fracture or chipping does not occur at the cutting edge, and which realizes excellent cutting performance over long periods. Moreover, a method of manufacturing a gear cutting tool including: a step for quenching a tool material comprising high-speed tool steel and which has been rough processed to a shape corresponding to a final shape of a gear cutting tool, to transform a structure of the tool material into martensite, a step for temperling the tool material after quenching to transform any residual austenite dispersingly distributed throughout a matrix of the martensite structure formed by the quenching, into martensite, and a step for finishing the tool material after tempering to a final shape, is characterized in that the tool material after quenching is subjected to sub-zero treatment involving cooling and holding at a temperature of less than &minus;150&deg; C.

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Tokyo, Japan

Natsuki Ichimiya