低压烧结制备石墨烯增强WC-Co硬质合金

采用机械搅拌和静电吸附2种工艺制备氧化石墨烯增强WC-Co复合粉末，对复合粉末的微观形貌进行表征，并利用低压烧结工艺制备石墨烯增强WC-Co硬质合金，对硬质合金力学性能进行测试分析。静电吸附工艺和低压烧结相结合所制备的石墨烯增强WC-Co硬质合金抗弯强度和维氏硬度分别为3 250 MPa和1 846，比不添加石墨烯的WC-Co硬质合金抗弯强度和硬度分别提高了38.92%和7.93%；比机械搅拌工艺和低压烧结相结合所制备的石墨烯增强WC-Co硬质合金抗弯强度提高了8.33%，硬度略有提高。石墨烯通过静电吸附工艺均匀地分散在WC-Co基体中，高温烧结时通过阻碍晶界的扩散和位错的滑移来细化晶粒，有裂纹产生时会阻碍裂纹扩展，从而增强材料力学性能。

Graphene Reinforced WC-Co Cemented Carbide Prepared by Low Pressure Sintering

Graphene oxide reinforced WC-Co composite powders were prepared by mechanical stirring and electrostatic adsorption, respectively. The micro-morphology of the composite powders was characterized. Graphene reinforced WC-Co cemented carbide was prepared by low-pressure sintering process, and its mechanical properties were tested and analyzed. The bending strength and Vickers hardness of the graphene reinforced WC-Co cemented carbide were 3 250 MPa and 1 846 respectively, which were 38.92% and 7.93% higher than those of the WC-Co cemented carbide without graphene. The bending strength is increased by 8.33% than that of the graphene reinforced WC-Co cemented carbide prepared by the mechanical stirring process and low-pressure sintering, and the hardness is slightly increased. The graphene added by electrostatic adsorption process is uniformly dispersed in the WC-Co matrix. During high temperature sintering, the grains are refined by hindering the diffusion of grain boundaries and the slip of dislocations. When cracks are generated, the crack propagation is hindered, thereby enhancing the mechanical properties of the material.