The Co composite powder doped with Y2O3 was prepared by planetary grinding,the WC-Co mixed powder containing Y2O3 was prepared by adding WC powder,and then WC-Co-Y2O3 cemented car-bide was prepared by SPS.Scanning electron microscope,energy spectrum analyzer,X-ray diffractometer,Vickers hardness tester and friction and wear testing machine were used to investigate the effects of ball milling time on the microstructure and phase composition of Co-1%Y2O3 composite powder,and ball mil-ling time and Y2O3 content on the microstructure,phase composition,density,Vickers hardness,fracture toughness and wear resistance of WC-Co-Y2O3 cemented carbide.The results show that the Co diffraction peak shifts towards a larger angle after adding Y2O3 and ball milling.As the ball milling time increases,the Co grains are disrupted and their size becomes smaller,leading to a decrease in the intensity of Co diffrac-tion peak.The density,Vickers hardness and fracture toughness of the cemented carbide increase with the extension of ball milling time.When the ball milling time exceeds 36 h,the hardness of the cemented car-bide tends to stabilize,while the fracture toughness decreases.The density,Vickers hardness,fracture toughness and wear resistance of the cemented carbide first increase and then decrease with the increase of Y2O3 content.The best overall performance of the cemented carbide is obtained when the Y2O3 content is 1%.The addition of rare earth oxide Y2O3 by stepwise ball milling can strengthen the Co binder,inhibit the growth of WC grains,and enhance the mechanical properties of the cemented carbide.
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