混杂增强(CNTs+TiB2)/Cu复合材料制备与性能

Preparation and Properties of Hybrid Reinforced (CNTs+TiB2)/Cu Composites

摘要:

本文以碳纳米管（CNTs）和TiB2颗粒作为增强相，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在铜基复合材料中易团聚问题。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，当含量为0.1 wt.%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252 MPa。而球磨后热压烧结的1 wt.% TiB2/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TiB2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(CNTs+TiB2)/Cu复合材料。相比单一CNTs（或TiB2）增强铜基复合材料，(CNTs+TiB2)/Cu复合材料的强度提升显著。其中，(0.1 wt.% CNTs+1 wt.% TiB2)/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 wt.% TiB2/Cu，其导电率仅降低3.3%，而抗拉强度则升高21.8%。这主要归因于片层间CNTs可起承担和传递载荷作用，同时片层间弥散分布的TiB2颗粒可以钉扎位错，两种强化机制共同作用使(CNTs+TiB2)/Cu复合材料的抗拉强度显著提升。

Abstract:

The effects of single and hybrid reinforcement of carbon nanotubes (CNTs) and TiB2 particles on the microstructure, density, electrical conductivity, hardness and tensile strength 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 density and electrical conductivity of the sintered CNTs/Cu composites decreased with the increase of the CNTs content, while the tensile strength and elongation first increased and then decreased with the increase of the CNTs content. The comprehensive performance is the best when the content is 0.1 wt.%, and the density, electrical conductivity and tensile strength are 97.57%, 91.2 %IACS and 252 MPa respectively. Meanwhile, the density, electrical conductivity and tensile strength of the sintered 1 wt.% TiB2/Cu composite after ball milling are 97.61%, 58.3 %IACS and 436 MPa, respectively. Finally, hybrid reinforced (CNTs+TiB2)/Cu composites were prepared by introducing in situ TiB2 particles into CNTs/Cu composites with brick structure. Compared with single CNTs (or TiB2) reinforced copper matrix composites, the strength of CNTs and TiB2 hybrid reinforced composites is significantly improved. When 0.1 wt.% CNTs and 1 wt.% TiB2 were mixed, the composite density, electrical conductivity and tensile strength were 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% when compared with 1 wt.% TiB2/Cu. It is mainly attributed to the role of CNTs in carrying and transferring loads, and the pining dislocations of the dispersed TiB2 particles. The two strengthening mechanisms work together to significantly improve the tensile strength of (CNTs+TiB2)/Cu composites.