Abstract:The allotropic transformation process of the γ-phase in WC-Co cemented carbides has been explored.The concepts of γ-grain and the γ-domain have been proposed forward:The γ-domain is the residual FCC-type β-Co grain that failed to transform when cooling alloy sample and γ-base is the HCP-type x-Co transformed mainly by means of diffusion,the outline of the γ-grain is consistent with the newly fromed β-Co grain formed at high temperature.The quantity and distribution of γ-grain domain are related to the cooling rate after sinter- ing and influence the alloys properties.

Key words: WC-Co cemented carbides; γ-grain; γ-domain