Nippon Tungsten Co., Ltd.

Shigeya Sakaguchi

Hiroshi Ito

Kei Tokumoto

Masaharu Shiroyama

Mitsuyoshi Nagano

Kenji Nakahara

Toyoshige Sasaki

Shigeru Matsuo

Kenji Okamura

Masahiro Yamauchi

Kouki Minamoto

Hironobu Shinoaki

Koichi Ibusuki

Shouji Eguchi

Kohei Kitahara

Norimitsu Mukae

Tetsunori Kitada

Disclosed is a fire-resistant lead-free shield material having high shielding ability against nuclear or electromagnetic radiation, and excellent bending workability and handling performance. The shield material comprises a composite material consisting of an organic material and a metal or metal compound having a nuclear or electromagnetic radiation-shielding ability. The composite material is formed into a given shape, such as a plate shape, and wrapped with a cloth-like sheet formed of glass fibers, metal fibers or carbon fibers. Alternatively, the shield material comprises a shielding element consisting of an elastic polymeric organic compound and a particle having a nuclear or electromagnetic radiation-shielding ability, such a heavy metal or ferrite. The shield material also includes either one of a film made of polyethylene, nylon, polyester or metal, a wire mesh formed of nylon fiber or metal fiber, and a plate- or rod-shaped member having a surface formed with a protrusion, which is compression-bonded onto or in the vicinity of a surface of the shielding element, or inside the shielding element.

Shield material

A WC-based composite ceramics sintered body consisting of 40 volume % to 90 volume % of WC including solid-solved oxygen represented by a chemical formula of WC O (where 0.005<y/x&plus;y<0.05), with the remainder being partially stabilized ZrO and inevitable impurities, wherein partially stabilized ZrO includes one or more of stabilizers selected from the group consisting of Y O , CeO and MgO. A prepared powder of raw material is held in an atmosphere containing oxygen in a temperature range of 200&deg; C. to 600&deg; C. for 0.1 hour to 3 hours to provide WC grains including solid-solved oxygen represented by a chemical formula of WC O (where 0.005<y/x&plus;y<0.05). Partially stabilized Zro including one or more of stabilizers selected from the group consisting of Y O , CeO and MgO is used as a phase for filling up the grain boundary of the WC grains. A ceramic sintered body capable of sufficiently fulfilling various properties, such as of Young's modulus, hardness, heat conductivity and electrical workability, which are required as materials for sliding parts, edged tools and dies can be obtained.

WC-base composite ceramic sintered compact

A die cut roll includes a rotary driving roll having projecting pressure cutting blades on a surface thereof formed in accordance with the shape of a product to be cut to thereby form a die cutter and an anvil roll adapted to receive an edge of each of the projecting pressure cutting blades of the die cutter. The rotary driving roll includes inclined finishing surfaces formed adjacent to a top smooth portion of an edge of each of the projecting pressure cutting blades by a grinding process so that the inclined finishing surfaces have grinding flaws which make an angle &phgr; of 50&deg;-90&deg; to ridgelines defining the top smooth portion.

Die cut roll

A titanium-base sintered alloy which comprises a TiC and/or TiN or Ti(C,N) solid solution accounting for 5 to 70 vol %, with the remainder being composed of two components. The first component is at least one species selected from the group consisting of Groups Va and VIa metallic elements, except Cr, or at least one species selected from the group consisting of carbides, nitrides, and carbonitrides of Groups Va and VIa metallic elements, except Cr. The second component is titanium. The first component accounts for 1 to 30 vol % and the second component accounts for 70 to 99 vol % of the total amount of the first and second components. The alloy produces a preferred result when the content of TiC or TiN is 35 to 70 vol % and the first component accounts for 1 to 15 vol % of the remainder. It is desirable that the TiC, TiN, and the first component of the remainder be in the form of a solid solution. This alloy exhibits improved wear resistance, strength, and specific strength without any loss in corrosion resistance.

Titanium-base hard sintered alloy

Tungsten carbide and nickel-phosphorus alloy coexist in individual particles. The composite powder produced by a mechanical mix of these two substances consists of 30.about.95 percent by weight of tungsten carbide and valanced nickel-phosphorus alloy. This powder is sprayed to the ferrous base material, resulting in a uniform dispersion of both tungsten carbide and nickel-phosphorus, causing tight adhesion to the surface because the tungsten carbide and nickel-phosphorus alloy coexist in individual particles in the composite. A hard metal coating is produced having high hardness and excellent wear resistance, after the surface of the hard metal coating is heated and the high temperature of the nickel-phosphorus alloy causes a liquid phase under the condition of a nonoxidizing atmosphere. This hard metal coating is used for various kinds of the wear-resistant materials.

Method for hardfacing a ferrous base material

This invention relates to the manufacture of a mechanical seal ring provided with a cemented carbide hardened layer or ring which is firmly bound to a substrate of a mechanical seal ring and is of sufficient hardness. The method is substantially characterized by the use of Ni--P alloy as a binder between the cemented carbide layer and the substrate. In the manufacturing process, after a presintered carbide compact made of hard carbide powder such as tungsten carbide powder is applied to a groove of the substrate, the Ni--P alloy in either paste form or compacted and sintered compact form is applied onto the presintered carbide compact and finally is sintered in a non-oxidizing furnace. In the above sintering process, Ni and P infiltrates and diffuses into the substrate and the presintered carbide compact whereby the cemented carbide hardened layer and the substrate can be firmly bound to each other due to the metallurgical bonding therebetween.

Method for manufacturing a mechanical seal ring

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Fukuoka, Japan

Shigeya Sakaguchi