碳纳米管增强铜基复合材料的制备、力学性能及电导率

以CNTs、电解Cu粉、Cu(CH_3COO)_2·H_2O为原料,采用混酸处理、分子水平法结合行星球磨两步混合工艺制备含0.5%～2%(质量分数)CNTs的Cu基复合粉末,然后通过放电等离子烧结技术制备了Cu-CNTs复合材料,探讨了制备工艺及CNTs含量对Cu-CNTs复合材料的组织、电导率和力学性能的影响规律。结果表明:当CNTs含量小于1.0%时,采用两步混粉工艺制备的Cu-CNTs复合粉体均匀性、分散性良好,经烧结后可获得致密度高、CNTs分布均匀的Cu-CNTs复合材料;当CNTs含量大于1.0%时,复合材料的致密度及CNTs分布均匀性明显降低;随CNTs含量的提高,复合材料的强度先升高后降低,塑性和电导率趋于降低;相对高能球磨、分子水平法等单一混粉工艺而言,两步法制备的Cu-1.0%CNTs复合材料综合性能更优,其电导率为51.7 MS/m(89.1%IACS),维氏硬度为1130 MPa,抗拉强度为279 MPa,断后伸长率为9.8%。

Preparation, mechanical properties and electrical conductivity of carbon nanotube reinforced Cu matrix composites

The copper based composite powders containing 0.5~2wt.% CNTs were prepared by molecular-level method combined with the two-step mixing process using CNTs, electrolytic Cu powder and Cu (CH₃COO) ₂.H₂O as raw materials, and then the Cu-CNTs composites were prepared by spark plasma sintering. The influence of preparation process and CNTs content on the microstructure, electrical conductivity and mechanical properties of Cu-CNTs composites were studied. The results show that when CNTs content is less than 1.0wt.%, Cu-CNTs composite powders prepared by two-step mixing process have good homogeneity and good dispersibility. The Cu-CNTs composites with high density and uniform CNTs were obtained after sintering. When the content of CNTs is more than 1.0wt.%, the densities and the uniformity of CNTs are obviously decreased. With the increase of the CNTs content, the strength of composites increases in initial stage and then declines, and the plasticity and electrical conductivity tend to decrease. Compared with the high-energy ball milling and molecular level method, the Cu-1.0wt.%CNTs composites prepared by two-step method exhibits the superior mechanical properties, including the electrical conductivity of 51.7 MS/m (89.1% IACS), the hardness of 113 HV, the tensile strength of 279 MPa, and the elongation of 9.3%.