混杂增强(CNTs+TiB_(2))/Cu复合材料的制备与性能

Preparation and Properties of Hybrid Reinforced(CNTs+TiB_(2))/Cu Composites

以碳纳米管(CNTs)和TiB_(2)颗粒作为Cu基复合材料的增强相,研究了不同体系复合材料的组织和性能。首先利用球磨、表面吸附和热压烧结相结合技术制备具有层叠结构的CNTs/Cu复合材料,改善了CNTs在Cu基复合材料中的易团聚问题。CNTs/Cu复合材料的致密度和导电率随CNTs含量增加而降低,抗拉强度和伸长率随CNTs含量增加先升高后降低,当CNTs含量为0.1%(质量分数,下同)时综合性能最优,致密度、导电率和抗拉强度分别为97.57%、91.2%IACS和251 MPa。而球磨后热压烧结的1%TiB_(2)/Cu复合材料致密度、导电率和抗拉强度分别为97.61%、58.3%IACS和436 MPa。在此基础上,将TiB_(2)颗粒原位引入到具有层叠结构的CNTs/Cu复合材料,制备获得混杂增强的(CNTs+TiB_(2))/Cu复合材料。相比单一CNTs(或TiB_(2))增强的Cu基复合材料,(CNTs+TiB_(2))/Cu复合材料的强度提升显著。其中,(0.1%CNTs+1%TiB_(2))/Cu复合材料的导电率和抗拉强度分别为56.4%IACS和531 MPa,相比1%TiB_(2)/Cu,其导电率仅降低3.3%,而抗拉强度则升高21.8%。这主要是由于片层间CNTs可起承担和传递载荷的作用,同时片层间弥散分布的TiB_(2)颗粒可以钉扎位错,2种强化机制的共同作用使(CNTs+TiB_(2))/Cu复合材料的抗拉强度显著提升。

The effects of single and hybrid reinforcement of carbon nanotubes(CNTs)and TiB_(2) particles on the microstructure,density,electrical conductivity,hardness and tensile property of copper matrix composites were studied.Firstly,CNTs/Cu composites with brick structure were prepared by the combined preparation technology of ball milling,surface adsorption and hot-pressing sintering,which solved the problem of agglomeration of CNTs.The relative density and electrical conductivity of the sintered CNTs/Cu composites decrease with the increase in the CNTs content,while the tensile strength and elongation firstly increase and then decrease with the increase in the CNTs content.The comprehensive performance is the best when the CNTs content is 0.1wt%,and the relative density,electrical conductivity and tensile strength are 97.57%,91.2%IACS and 251 MPa,respectively.Meanwhile,the relative density,electrical conductivity and tensile strength of the sintered 1wt%TiB_(2)/Cu composite are 97.61%,58.3%IACS and 436 MPa,respectively.Finally,hybrid reinforced(CNTs+TiB_(2))/Cu composites were prepared by introducing in situ TiB_(2) particles into CNTs/Cu composites with brick structure.Compared with single CNTs(or TiB_(2))reinforced copper matrix composites,the strength of CNTs and TiB_(2) hybrid reinforced composites is significantly improved.When 0.1wt%CNTs and 1wt%TiB_(2) were mixed,the composite relative density,electrical conductivity and tensile strength is 97.21%,56.4%IACS and 531 MPa,respectively.And the electrical conductivity decreases by 3.3%,while the tensile strength increases by 21.8%compared with 1wt%TiB_(2)/Cu.It is mainly attributed to the role of CNTs of carrying and transferring loads,and the role of dispersed TiB_(2) particles for the dislocations pining,the two strengthening mechanisms work together to significantly improve the tensile strength of(CNTs+TiB_(2))/Cu composites.