Research On Nanocrystalline WC-8 (Fe,Co,Ni)RE Cemented Carbide

Cemented carbide has high hardness,high melting point,good wear resistance and large elastic modulus,especially has higher hardness at higher temperatures. Tungsten-cobalt cemented carbide,namely,WC-Co cemented carbide has excellent physical,and mechanical properties,high bending strength and toughness,good thermal conductivity in all kinds of the cemented carbide.WC-Co cemented carbide plays a very important role in the modern wear-resistant materials and high temperature-corrosion resistant materials,and is widely applied in metallurgy, machinery and other fields.However,because of the long-term shortage of Co resources in our country,the output of Co can not meet its demands,the substitute of Co is needed to be sought urgently.In this paper,it is studied that the low-cost Fe and Ni which has similar nature and structure with Co was replaced part of Co.In the paper,the WC-8(Fe,Co,Ni)RE cemented carbide was prepared by the high-energy ball milling,and its mechanical properties and microstructure were researched mainly.With the comparison between the cemented carbide that ironnickel replacing for cobalt and the traditional cemented carbide,the results has been shown that the sintering temperature of WC-8(Fe,Co,Ni)RE cemented carbide is obviously higher than the YG's cemented carbide.The liquid phase sintering could be achieved while the sintering temperature is 1430℃,and a better density could be acquired while the sintering temperature is higher than 1430℃.While the proportion of Fe,Ni and Co was 65:20:15 or 60:20:20,the hardness of the cemented carbide was about 90.6HRA,the sintered product could be a fully dense state nearly,and its performance exceeds the traditional YG8 carbide.The growth of WC crystal could be restrained by putting in 1wt%additive of rare earth,and the mechanical properties of the cemented carbide could be also improved.There is rising space in improving the performance of the Fe-Co-Ni carbide,however,because of its high sintering temperature,it is doomed that the growth of WC grain in Fe-Co-Ni carbide will be larger and its performance will be not good as the YG's carbide.