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Nishi-Tokyo-shi, Japan

Kunimoto T.,Ehime University | Irifune T.,Ehime University | Irifune T.,Tokyo Institute of Technology | Tange Y.,Japan Synchrotron Radiation Research Institute | Wada K.,Fuji Die Co.
High Pressure Research | Year: 2016

A pressure generation test for Kawai-type multianvil apparatus (KMA) has been made using second-stage anvils of a newly developed ultra-hard tungsten carbide composite. Superb performance of the new anvil with significantly less plastic deformation was confirmed as compared to those commonly used for the KMA experiments. A maximum pressure of ∼48 GPa was achieved using the new anvils with a truncation edge length (TEL) of 1.5 mm, based on in situ X-ray diffraction measurements. Further optimization of materials and sizes of the pressure medium/gasket should lead to pressures even higher than 50 GPa in KMA using this novel tungsten carbide composite, which may also be used for expansion of the pressure ranges in other types of high pressure apparatus operated in large volume press. © 2016 Taylor & Francis Source


Provided is a high hardness ultra-fine cemented carbide with a Ni binder phase for a wear resistant tool. An ultra-fine cemented carbide having high specularity and/or high strength, high hardness, and high wear resistance is obtained by using an ultra-fine raw powder of WC, controlling the amount of Ni, and the contents of V and Cr, so that a third phase containing V and Cr precipitates in a microstructure of the cemented carbide in a finely dispersed state, and at the same time, the size of Ni pool is controlled to a value equal to or less than the average grain size of WC. By using this cemented carbide, the range of application to an aspherical glass lens mold, an ultrahigh pressure generation container for neutron diffraction experiment, a non-ferromagnetic corrosion resistant and wear resistant tool, and the like is expanded.


Trademark
Fuji Die Co. | Date: 2009-10-27

Machine tools for the cutting, forming, shaping and moving of materials, namely, hard metal tools, carbide tools, metal rolls, carbide rolls, dies, plugs, punches, grinding rods, and carbide tips.


Kawakami M.,Fuji Die Co. | Kitamura K.,Fuji Die Co.
Materials Transactions | Year: 2015

The segregation of V and Cr at WC/Co and WC/WC interfaces in ultrafine-grained WC-0.7VC-1.4Cr3C2-10Co (mass%) cemented carbides produced through solid-state sintering and semi-sintering was investigated. This segregation was compared against that of a liquid-statesintered specimen to elucidate the mechanism by which WC grain growth is inhibited by Vand Cr. The Vand Cr were found to segregate at the WC/Co and WC/WC interfaces during solid-state sintering and semi-sintering, but no differences were observed in the Vand Cr concentrations at the interfaces among the liquid-state-sintered, solid-state-sintered and semi-sintered specimens. Furthermore, these concentrations were unchanged by quenching of the solid-state-sintered specimen. From these results, it was concluded that (V,W,Cr)Cx segregation layers are stably formed at the WC/Co and WC/WC interfaces at a temperature below the solidus of the Co phase, but almost dissolve in the liquid Co phase once the temperature exceeds its liquidus. Thus, the (V,W,Cr)Cx segregation layers observed at the WC/Co and WC/WC interfaces at room temperature are formed during the cooling that follows the liquid-state sintering. This supports the finding that WC grain growth is inhibited by the adsorption of dopant atoms onto steps/kinks on the WC surface during liquid-state sintering, as well as by the segregation layers formed on the WC surface during solid-state sintering. © 2015 The Japan Institute of Metals and Materials. Source


Kawakami M.,Fuji Die Co. | Kitamura K.,Fuji Die Co.
International Journal of Refractory Metals and Hard Materials | Year: 2015

Abstract The WC/WC interface in VC-doped submicron-grained WC-Co cemented carbides was investigated using high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray microanalysis (XMA) spectroscopy. Both V and Co were segregated at WC(0001)/WC(0001) or WC(0001)/WC(randomly oriented plane) interfaces and were slightly segregated at WC(101¯0)/WC(101¯0) or WC(101¯0)/WC(randomly oriented plane) interfaces. The V concentrations at these interfaces were 6-14 at.% and 2-6 at.%, respectively, and the Co concentrations were 7-20 at.% and 4-28 at.%, respectively. The V concentration depended on the WC crystallographic orientation, whereas the Co concentration had a small correlation. On the basis of this result and the previous results for the WC/Co interface, it is concluded that the segregation of V at WC/WC interfaces occurs by the same mechanism as that at WC/Co interfaces. In particular, rather than equilibrium segregation occurring during the heating and holding stages of sintering, segregation onto the WC surface proceeds during the cooling stage of the sintering process. © 2015 Elsevier Ltd. Source

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