硬質材料 反応ほう化とう結法による高強度複ほう化物系硬質材料の開発

Abstract

Borides are promising candidates for wear resistant materials. But poor sinterability and extreme brittleness of borides retarded the fabrication of bulk materials. This paper gives criteria for the development of boride base cermets. Reaction boronizing sintering developed by us is a novel strategy to form a ternary boride coexisting with a binder metal during sintering associated with liquid phase formation. This new sintering technique has successfully brought development of three ternary boride base cermets such as Mo2FeB2, Mo2NiB2 and WCoB base ones. This paper describes the sintering behavior, mechanical properties, microstructure and phase formation related with the alloying elements on Mo2NiB2 boride base cermets. This paper also illustrates Reitveld analysis results of the complex boride structure in the cermets.