Abstract
It was found by the present authors that Co pools generally formed in the microstructure of WC-Co alloy. Then, the influence of Go pools on the strength of the alloy and the cause of formation of Co pools were examined. The following results were obtained.
(1) The formation of Co pools resulted from the flaky powder, that is, Co rich WC-Co agglomerates which appear in the mixed powder during ball-milling. The flaky powder often formed, when the mixture was ball-milled by using stainless-steel pot. Then, the mechanism of formation of flaky powder was discussed. (2) The strength of usual alloy having Co pools in the structure was always lower than that of the alloy free from Co pools. The lower strength of usual alloy was owing to the fact that Co pools were apt to act as a fracture source.
