配碳量对WC-CoNiFeCrMo硬质合金微观组织与力学性能的影响OA

Traditional cemented carbides typically use Co as the binder.In recent years,novel cemented carbides employing high-entropy alloys as substitutes for Co have demonstrated significant advantages in improving hardness,fracture toughness,high-temperature oxidation resistance,and corrosion resistance.In cemented carbides with Cr-and Mo-containing high-entropy alloy binders,the strong carbide-forming elements Cr and Mo influence the carbon content in the binder phase and the existing form of carbon in the alloy,thereby affecting the mechanical properties.This work aims to investigate the influence mechanism of carbon addition on the microstructure and grain growth of WC-CoNiFeCrMo cemented carbides,and to explore the variation patterns of their mechanical properties.The results show that with increasing carbon addition,the WC grain size in the WC-CoNiFeCrMo alloy changes slightly,the coercive force gradually decreases,and the hardness decreases slightly.The fracture toughness and transverse rupture strength of the alloy first increase and then decrease,reaching peak values when the total carbon content of the alloy increases to 5.73%(mass fraction),with a fracture toughness of 18.52 MPa·m1/2 and a transverse rupture strength of 2991 MPa.With further increase in carbon addition,carburized phases appear in the alloy,and the fracture toughness and transverse rupture strength decrease significantly.