Effect of VC and NbC additions on microstructure and properties of ultrafine WC- 10Co cemented carbides

摘要

The nanocomposite WC-Co powders were prepared through planetary ball milling method.Effects of grain growth inhibitor addition and the vacuum sintering parameters on the microstructure and properties of ultrafine WC-10Co cemented carbides were investigated using X-ray diffractometer,scanning electron microscope and mechanical property tester.The results show that VC and NbC additions can refine the WC grains,decrease the volume fraction of Co3W3C phase in ultrafine WC-10Co cemented carbides,and increase the hardness and fracture toughness of the base alloys.After sintering for 60 min at 1 400℃,the average grain size and hardness of ultrafine-grained WC-10Co-1VC cemented carbide are 470 nm and HRA 91.5,respectively.The fracture toughness of cemented carbide WC-10Co-1NbC alloy is over 7 MN·m -3/2 .