Effect Of Inhibitor On Ultrafine Graened Cemented Cardedes

In this paper, different content of mixed VC/Cr3C2 or (TaNb)C /Cr3C2 were added to WC-12%Co according to orthogonal experimental design. The effects of inhibitors on the sintering character, properties and microstructure of superfine cemented carbides are studied.Results show that when different kinds of inhibitors are added at the same time in proper content, the alloys' WC grains are fined. They are helpful to enhance the properties of the alloys. When 0.5%Cr3C2/0.3% VC are added ,the bb of superfine grained hardmetal reaches 3786 MPa,the hardness is 91.7HRA and the alloys' WC grains are under 0.6 m. When 0.3% Cr3C2/0.4% (TaNb) C are added ,the bb of superfine grained hardmetals reach 3790 MPa, the hardness is 91.6 HRA and the alloys' WC grains are under 0.8 m and have no abnormal grains growth. The vacuum and HIP sintering process is very helpful to enhance properties of superfine cemented carbides with addition agent, especially for alloys with less Co , because vacuum and HIP sintering process can reduce alloys' porosity effectively .During the sintering process, the inhibitor will impede the densification of alloys' solid-phase sintering and decrease liquid occurrence temperature.At last, the paper discusses the mechanisms of inhibitors on superfine grained cemented carbides in detail.