【摘要】 配制两批不同总碳为5.66%和5.70%的混合料,在不同烧结温度下制备WC-9Co（含0.8%的Cr₃C₂/VC）超细晶硬质合金,检测了混合料中氧含量及WC晶粒大小、应变随球磨时间的变化情况,研究了不同烧结温度下WC-9Co硬质合金的磁学性能随球磨时间的变化。结果表明,滚动球磨不能破坏晶粒尺寸达到纳米级的WC原料微观晶粒;不同总碳混合料随球磨时间延长其氧含量均呈上升趋势,符合线性规律,但高总碳的混合料中氧含量上升速度较慢;超细晶硬质合金的Com值（即碳含量）是影响H_c值的主要因素,随Com值增加H_c先升高后降低并呈抛物线规律,在特定的Com值达到最大值,据此可以推测其主要原因是硬质合金碳含量影响Cr、V元素在WC/Co界面析出形成抑制WC晶粒长大的（W,Cr）C_x和（W,V）C_x界面相,进而影响抑制效果。更多还原

【Abstract】 WC-9Co（containing 0.8% Cr₃C₂/VC）ultrafine cemented carbides were prepared at different sintering temperature by using mixture with different total carbon content of 5.66% and 5.70%.Change with ball milling time in the oxygen content of the mixture,size and internal strain of WC grains was measured,and the change of magnetic properties in the WC-9Co cemented carbides sintered at different temperatures with ball milling time was also investigated.The results show that the nano-size WC grains cannot be crushed by rolling ball milling.With the increase of ball milling time,the oxygen content of mixture with different carbon contents linearly increases,and the increase rate is slower with higher carbon content.Com value of the ultrafine cemented carbides is a main factor affecting H_cvalue.H_cvalue increases at first and then decreases with the increase of Com value showing aparabolic law,and the maximum H_cvalue is reached at a certain Com value.It can be deduced that the carbon content affects the precipitation of V and Cr on the WC/Co interface and the formation of（W,Cr）C_xand（W,V）C_xinterphases which can inhibit the growth of WC grains,and therefore affects the inhibition effect.更多还原