The attainment of both hardness and fracture toughness is the critical requirement for cemented carbides to be applied as structural and functional materials. However, these two properties are usually mutually exclusive. Traditional toughening methods as particle-dispersion, phase-transformation and whisker toughening usually impact the hardness adversely. This work was undertaken to develop a high-hard and high-tough cemented carbide through introducing multilayer graphene (MLG) as well as single layer graphene (SLG) as the reinforcing phase. The microstructure together with mechanical properties of the graphene reinforced cemented carbides was evaluated and compared. MLG exhibited a more favorable dispersion property in cemented carbide matrix than SLG. SLG addition was beneficial for increasing fracture toughness without appreciable influence on the hardness of cemented carbides, while MLG doping simultaneously enhanced the fracture toughness and hardness of the hardmetal with a fracture toughness of 13.2 MPa m^1/2, a hardness of 2057.2 kgf/mm² and a transverse rupture strength of 1709.2 MPa. This toughening mechanism constitutes a step forward in developing high-tough and high-hard cemented carbide matrix composites to be applied for structural as well as functional applications.

达到硬度和断裂韧性是硬质合金作为结构和功能材料应用的关键要求。然而，这两个属性通常是相互排斥的。传统的增韧方法如颗粒分散、相变和晶须增韧通常会对硬度产生不利影响。这项工作是通过引入多层石墨烯（MLG）和单层石墨烯（SLG）作为增强相来开发高硬度和高韧性硬质合金。评估和比较了石墨烯增强硬质合金的微观结构和机械性能。MLG 在硬质合金基体中表现出比 SLG 更好的分散性能。^1/2，硬度2057.2 kgf/mm ²，横向断裂强度1709.2 MPa。这种增韧机制在开发用于结构和功能应用的高韧性和高硬度硬质合金基复合材料方面向前迈进了一步。