碳纳米管增强硬质合金的制备及性能研究

为改善硬质合金中增强体碳纳米管（carbon nanotubes，CNTs）的团聚问题，采用化学镀Ni方法对CNTs进行表面改性，利用气压烧结工艺制备了WC-10Co-CNTs硬质合金和WC-10Co-CNTs/Ni硬质合金。对镀Ni前后CNTs的表面形貌、结构及成分进行了分析表征，并研究了CNTs和CNTs/Ni对硬质合金组织及性能的影响。结果表明，CNTs经化学镀改性处理后，表面包覆了致密的纳米Ni颗粒，团聚现象明显改善；在WC-10Co中添加CNTs或CNTs/Ni后可以有效地细化硬质合金的晶粒，降低孔隙率；和未添加的比较，添加质量分数0.1%的CNTs的硬质合金和添加质量分数0.1%的CNTs/Ni的硬质合金抗弯强度分别提高了17.5%和28.2%，热扩散系数分别提高了23.5%和42.8%。

Preparation and properties of carbon nanotube-reinforced cemented carbide

In order to reduce the agglomeration of reinforcing carbon nanotubes in cemented carbide, the surface of CNTs was modified by electroless nickel plating. CNTs reinforced WC-10Co cemented carbide as well as CNTs/Ni reinforced WC-10Co cemented carbide was prepared by gas pressure sintering process. The surface morphology, structure and composition of CNTs before and after Ni plating were characterized, and the effects of CNTs and CNTs/Ni on the structure and performance of cemented carbides. The results showed that the surface was covered with dense Ni nanoparticles after electroless plating, and the agglomeration of carbon nanotubes was significantly improved. With the addition of CNTs and CNTs/Ni, the grain of cemented carbide is effectively refined with less porosity. Compared to the unadded, the bending strength of the cemented carbide with the additive score of 0.1% CNTs and the cemented carbide with the additive score of 0.1% CNTs/Ni increased by 17.5% and 28.2%, and the thermal diffusivity increased by 23.5% and 40.8%, respectively.