石墨烯对气压烧结WC-Co硬质合金性能的影响

为了减小氧化石墨烯（graphene oxide，GO）在WC-10Co硬质合金中的团聚以及高温液相烧结过程中Co对GO的溶蚀作用，通过化学镀的方式制备了改性氧化石墨烯（GO/Ni），随后利用静电吸附以及机械搅拌两种方法分别制备了WC-10Co-GO复合粉体和WC-10Co-GO/Ni复合粉体。用扫描电子显微镜（scanning electron microscope，SEM）和透射电子显微镜(transmission electron microscope，TEM)对改性后的GO以及复合粉体进行微观形貌的表征。采用气压烧结工艺制备了WC-10Co、WC-10Co-GO和WC-10Co-GO/Ni硬质合金并研究了硬质合金的物理性能和力学性能。实验结果表明：随着GO和GO/Ni的加入，硬质合金的密度和洛氏硬度有了略微的降低；对比WC-10Co硬质合金，WC-10Co-GO和WC-10Co-GO/Ni硬质合金的横向断裂强度分别提升了35.2%和59.7%，其中GO/Ni作为作为基体增强相的效果最佳。

Effect of graphene on the properties of gas pressure sintered WC-Co cemented carbides

In order to reduce the agglomeration of graphene oxide (GO) in WC-10Co cemented carbides and the dissolution effect of Co on GO during high-temperature liquid sintering, the modified graphene oxide (GO/Ni) was prepared by electroless plating. Then WC-10Co-GO composite powder and WC-10Co-Go/Ni composite powder were prepared by electrostatic adsorption and mechanical stirring. The micro-morphologies of the modified GO and composite powders were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). WC-10Co, WC-10Co-GO and WC-10Co-GO/Ni cemented carbides were prepared by gas pressure sintering process, and the physical and mechanical properties of the cemented carbides were studied. The experimental results show that the density and Rockwell hardness of cemented carbide decrease slightly with the addition of GO and GO/Ni. Compared with WC-10Co cemented carbide, the transverse fracture strengths of WC-10Co-GO and WC-10Co-GO/Ni cemented carbides increase by 35.2% and 59.7%, respectively. Among them, GO/Ni as the matrix reinforcement phase has the best effect.