摘要
利用卧式搅拌高能球磨结合真空热压烧结制备CNTs/Cu复合粉体及材料,采用X射线衍射(XRD),扫描电子显微镜(SEM),电子探针(EPMA),拉伸试验和电导率测试研究复合稀土La-Ce含量对CNTs/Cu复合粉体及材料显微组织及性能的影响。结果表明:添加0.10%(质量分数)La-Ce有利于球磨中Cu晶粒的细化和CNTs在Cu基体中的弥散分布,细化CNTs/Cu复合材料烧结组织;在烧结过程中稀土在铜晶粒边界析出,析出物并没有形成新的化合物,而是La, Ce单质,呈粗棒状错落排布,在烧结颗粒边界填充部分烧结孔隙,从而提高复合材料的致密度和抗拉强度到97.61%和246.24 MPa。未加入La-Ce时, CNTs在铜基体中出现大量局部团聚,添加La-Ce稀土能够促进球磨过程CNTs的均匀分布,减少烧结过程由于CNTs团聚而与Cu基体形成的大量孔隙。添加量提高到0.20%时, La, Ce在烧结过程中与杂质吸附而成硬质相,并在烧结颗粒界面大量析出,复合材料电导率和抗拉强度比添加0.10%La-Ce时分别降低18.3%和13.1%。
Dispersion strengthened copper-base composites CNTs/Cu were fabricated by high energy ball milling and vacuum hot-pressing sintering. The effect of rare earth La-Ce content on the microstructure and properties of CNTs/Cu composite powder and the sintered materials were studied. The results showed that 0.10%(mass fraction) La-Ce addition in the CNTs/Cu composite powder could accelerate grain refinement, CNTs dispersion in the mechanical alloying process, sintering particles refinement and purification. And the rare earth elemental La-Ce separated out at the grain boundaries of Cu-matrix with a shape of sticks. These precipitates filled in the pore on the interface of sintering particles, so as to improve the relative density and tensile strength of the composite up to 97.61% and 246.24 MPa. The CNTs dispersed uniformly with 0.10% La-Ce addition than that of no La-Ce addition. La-Ce addition accelerated the dispersion of CNTs in the CNTs/Cu composite powder in the ball-milling process. The La-Ce separated out on the boundaries of sintering particles with the content of La-Ce increased to 0.20%, therefore the conductivity and tensile strength of the composite decreased by 18.3% and 13.1%.
作者
周蕾
许忠文
蔡晓兰
冯敏
Zhou Lei;Xu Zhongwen;Cai Xiaolan;Feng Min(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2019年第12期1297-1301,共5页
Chinese Journal of Rare Metals
基金
云南省高校金属粉体制备与设备开发科技创新团队支持计划项目(14051693)
云南省重大项目(2014FC001)资助
