Abstract: The nanometer WC-10Co(mass fraction)composite powders were prepared by high energy ball milling for short time and carbonation reaction using W,C and Co powders as raw materials.The phase composition and morphology of the composite powders after ball milling and carbonation reaction were analyzed by XRD and SEM.The phase transformations during the carbonation reaction were analyzed by themogravimetry and differential scanning calorimetry.The results show that the WC-10Co composite powders whose grain size was 95 nm were obtained by heating the mixed powders at 1 000℃ for 1 h after high energy ball milling for 3 h.However,with low carbon content,η-Co6W6C existed in the powders,and the growth of WC grains was incomplete.Heating at 1 100℃ for 1 h,the complete WC grains with polygonal platelet morphology could be obtained.As the prolongation of ball milling time,the η phase content of the composite powders after carbonation increased.