メカニカルアロイング処理による低Ｃｏ超硬合金の作製

Abstract

Hard metals containing small amounts of cobalt were prepared by mechanical alloying using a vibrational ball mill in Ar atmosphere under reduced pressure. The contamination in the hard metal during mechanical alloying was attributed to wear of vibrational balls and could be reduced by using hard metal balls. Although mechanical alloying treatment was effective for the hard metals containing less than 3 mass%Co, increasing in cobalt content resulted in the formation of η phase (Co3W3C).A mechanical alloyed WC-lmass%Co hard metal, sintered at 1773K for 1.2ks in a vacuum, showed finer structure and higher hardness than a mixed WC-1mass%Co one.