• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.340-341
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• 2006

High functional micro devices are demanded in a variety of fields. For realising such demands, development of high-precision micro-components installed in the devices are needed. To achieve high-precision in the mold processing of micro-components, the development of mold materials, i.e., the development of WC-Co hardmetal with higher hardness and fracture strength is essential, together with the developments of processing technology of high precision mold and mold-forming technology of high precision micro-components, etc. The role of development of the finer submicro-grained hardmetal in a NEDO national project aiming the integrated development of these all technologies and some results are mainly explained.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.334-335
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• 2006

WC/WC interface in VC mono-doped WC-10mass%Co submicro-grained hardmetals of $0.5\;{\mu}m$ was investigated together with WC/Co interface by using HRTEM and XMA. The thickness of V-rich layer and the analytical value of V at WC/WC interface were almost the same as those at WC/Co interfaces. These results, etc., suggested that the V-rich layers at both interfaces were not generated by an equilibrium segregation mechanism in the sintering stage, but generated by a preferential precipitation mechanism during the solidification of Co liquid phase in the cooling stage. Based on this suggestion, we succeeded in developing a nano-grained hardmetal with 100 nm $(0.1\;{\mu}m)$.