碳纳米管增强铜基复合材料的拉伸性能

摘要

采用粉末冶金方法制备不同体积分数的CNTs/Cu和Gra./Cu复合材料,分析两者的相对密度和硬度,考察其拉伸性能,并探讨各自的断裂机制.结果表明,相同增强体体积分数条件下,CNTs/Cu的相对密度和硬度均大于Gra./Cu,且在增强体体积分数为12%时达到最大值;CNTs/Cu的最大拉伸强度为81 MPa,Gra./Cu的最大拉伸强度77.5 MPa;CNTs/Cu的断裂形貌为沿晶断裂和穿晶断裂的混合断裂形貌,Gra./Cu的断裂形貌为沿晶断裂.说明纳米级的高强碳管能更加充分地填充在铜颗粒的间隙内,且具有大长径比,易弯曲缠绕,形成网状结构,可限制微裂纹的扩展,提高了铜基体的抗塑变能力.%The CNTs/Cu composites and Gra./Cu composites were fabricated by the powder metallurgy technique.In order to study the reinforcing properties of CNTs in copper matrix, the hardness,relative density,tensile strength and fracture mechanism of CNTs/Cu were studied compared with Gra./Cu.The results show that the hardness and relative density of CNTs/Cu achieve peak with 12% CNTs content,and are always bigger than those of Gra./Cu with the same reinforcement content;the maximum tensile strength is 81 MPa for CNTs/Cu and 77.5 MPa for Gra./Cu;CNTs/Cu display the mix fracture features of inter-grain and trans-grain,while Gra./Cu displays intergranular fracture.CNTs with high strength,distribu-ted in meshwork and acting as framework,could restrict the extending of crack and improve the strength and ductibility of the composites.