Research On Strengthening, Toughening And Surface Residual Stress Of WC-Co Cemented Carbide

Cemented carbides have been applied widely as excellent tool materials. It is meaningful to improve its properties by effective strengthening and toughening treatment. The research on the relation of surface residual stress and alloy performance has theoretical significance. In this paper, roll-milling technology and blasting shot process were applied on traditional cemented carbide for the first time. Optimized parameters were found to improve the flexural strength, hardness and wear-resistance. The magnitude and direction of surface residual stresses induced by roll-milling and blasting shot were investigated systematically by using X-ray diffraction method. It was found that surface residual stress of treated alloy increased significantly, and then the performance and service life of cemented carbide were improved. The surface residual stress state by heat treatment and deep-cooling treatment were analyzed. It was shown that the heat treatment and deep-cooling treatment have weak effect on the surface residual stress of cemented carbide. The main reason for performance improvement is the change of microstructure. The relation of residual stress and crack spread was also investigated. It was found that residual stress can restrain the spread of crack. The treated cemented carbides were put into practice; strengthening and toughening treatment improved both cutting efficiency and service life of cutters.