Study Of WC-10Co Cemented Carbide In Low Pressure Sintering Technology

WC-Co hardmetal is a kind of tool materials with good properties. With the development of nanocomposite technology and materials, it is imported in more and more fields which can resolve effectively the contradiction of strength and hardness in conventional cemented carbides. UP till now, none of companys can produce a cermet with grain size of less than 100 nm in the world. This is because that the current technology can't effectively control WC crystal growth during sintering. Scientific researchers over the world are having been applied themselves to synthesizing nanocomposite powder, sintering hardmetals with new technology and inducting crystal growth inhibitors in new way.In this study, Jiangzuan company offers us 0.6μm WC and 0.8μm Co power, I add WC power Co power and inhibitors in a pot, take liquid grain alcohol as mediμm of ball milling. The mill ball contrast to material is 10:1, add plasticizer to the pot during the ball milling, drμm's speed of rotation is 92r/min. Screen separation is just after ball milling, than put the specimen in vacuμm drying oven to desiccation, after that put it on tabletmachine to quash formation and put it into overpressure furnace that make use of overpressure sintering, at last test and measurement the alloy's performance. SEM, metallographic microscope and hardness test machine, etc. are used to characterize the WC-Co hardmetal. At the same time, we observation different temperature, sinter time and holding time, etc. to the influence of hardness character, except that, emphsis analysis if add different kind of inhibitors and different quantitative inhibitors is how to influence cemented carbide's qualitative.Results show that: the grain growth inhibitors VC and Cr₃C₂ are obvious slender when after ball milling, and the grain size of VC is smaller than Cr₃C₂, with added more thin grain growth inhibitors that degree of hardness and coercive force of hardmetal are all became better than before. Simultaneity found that the inhibiting effect is better when add VC and Cr₃C₂ composition inhibitors contrast to single VC or Cr₃C₂. When add 0.6VC(wt%)and 0.4Cr₃C₂(wt%), found the sinter temperature is 1360℃ and holding time 30 minutes that we can obtain average grain size is 300-400 nanometer and the degree of hardness is HRA92.3 high quality superfine WC-Co cemented carbide.