Microstructure evolution and mechanical properties of carbon nanotubes reinforced Al matrix composites
Microstructure evolution and mechanical properties of carbon nanotubes reinforced Al matrix composites
复制标题
碳纳米管增强铝基复合材料的微观结构演变及力学性能
DOI：
10.1016/j.matchar.2017.09.036
复制
发表时间：
2017
影响因子：
4.7
通讯作者：
Yi Jianhong
中科院分区：
文献类型：
--
作者：
Liu Xiaoqing;Li Caiju;Eckert Juergen;Prashanth Konda Gokuldoss;Renk Oliver;Teng Long;Liu Yichun;Bao Rui;Tao Jingmei;Shen Tao;Yi Jianhong
采用球磨和粉末冶金相结合的方法制备了碳纳米管增强纯铝（CNT/Al）复合材料。研究了碳纳米管的分布、粉末混合物和制备的复合材料块体的平均Al晶粒尺寸的演变，并测试了复合材料的力学性能。随着球磨时间的增加，缠结的碳纳米管被打破，逐渐实现在Al基体中的均匀分散。粉末混合物和挤压复合材料的显微组织变得更加致密，Al晶粒得到显著细化。用透射电镜（TEM）观察到沿着Al晶界分布的小尺寸Al 4C 3针状物.原位生成的Al 4C 3棒与Al基体具有Al 4C 3 [110]//Al [1 <$12]的取向关系，这大大提高了Al-CNT界面结合。随着球磨时间从2 h增加到12 h，复合材料的屈服强度和抗拉强度显著增加，球磨12 h的复合材料屈服强度和抗拉强度分别达到210±4.2 MPa和253±3.7 MPa。力学性能的提高主要是由于碳纳米管的均匀分布、Al基体的晶粒细化和原位生成的Al 4C 3。
Carbon nanotubes reinforced pure aluminum (CNT/Al) composites were fabricated by combined ball milling and powder metallurgy (PM) techniques. The distribution of CNTs, the evolution of the average Al grain size of the powder mixtures and as-prepared composite bulks were investigated, and the mechanical properties of the composites were also tested. With increasing ball milling time, the entangled CNTs were broken, gradually achieving a uniform dispersion within the Al matrix. The microstructure became denser and the Al grains in the powder mixture and extruded composites got significantly refined. Some small-sized Al 4 C 3 needles along the Al grain boundaries were observed using transmission electron microscopy (TEM). The in-situ formed Al 4 C 3 rods have an orientation relation with the Al matrix as Al 4 C 3 [110]//Al [1¯ 12], which strongly improved the Al-CNT interface bonding. The yield and the ultimate tensile strength of the composites significantly increased, when the ball milling time increased from 2 to 12 h, finally reaching about 210±4.2 MPa and 253±3.7 MPa, respectively, for the composite milled for 12 h. The enhancement of mechanical properties mainly stems from the uniform distribution of CNTs, the grain refinement of the Al matrix and the in-situ formed Al 4 C 3.