Effect of multilayer graphene as a reinforcement on mechanical properties of WC-6Co cemented carbide

Different contents of graphene was added to the WC-6Co alloy powder to prepare cemented carbide by low pressure sintering. The microstructure, hardness, transverse rupture strength, fracture toughness and thermal conductivity of cemented carbide were investigated. The results show that graphene was distributed as a reinforcement at the Co phase, WC/WC interface and WC/Co interface. The hardness of the cemented carbide decreased slightly with the increase of graphene content. The transverse rupture strength increased first and then decreased with the increase of graphene content, and reached 2321.2 MPa when the content of graphene is 0.05 wt%. The fracture toughness increased to 13.1 MPa m(1/2) after adding 0.05 wt% graphene. The thermal conductivity of the sample with 0.05 wt% graphene was greatly improved. After comprehensive consideration, the cemented carbide with 0.05 wt% graphene has excellent performance and meet the performance indexes of high hardness, strength and toughness.