Study on sintering technology of cemented carbide

Based on the turbo-air stream classifying principle, the quality of superfine WC powder get further improving by means of superfine pulverizing grader. Experiments show that the technology of air steam classifying has significant effect on increase of the fineness and the particle classification efficiency. By comparing different type of air stream equipment, the QYF fluid-bed superfine pulverizing grader was adopted in the experiment that was manufactured by KunShan superfine pulverizers factory as well as obtaining high quality superfine WC powder with high homogeneous. Finally, the factor was studied that influence the densification and shrinkage, including the low-pressure sintering and inhibitor additions, experimental evidence indicates that Cr3C2 and VC is suitable to as inhibitor additions of ultra-fine cemented carbide. Also, an investigation on the relationship between grain growth and the amount of inhibitor additives was also made. High quality ultra-fine cemented carbide was manufactured with WC grain size lies in the average of 0.3-0.4μm, alloy hardness of higher than 93 and bending strength higher than 3300. The microstructure was found to be composed of very fine and uniform carbides.