碳纳米管增强开孔铝基复合泡沫的疲劳性能  

Fatigue performance of open-cell aluminium matrix composite foams reinforced by carbon nanotubes

作　　者：林森 杨旭东[1] 刘冠甫 胡琪 沙军威 LIN Sen;YANG Xudong;LIU Guanfu;HU Qi;SHA Junwei(Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]中国民航大学中欧航空工程师学院,天津300300 [2]天津大学材料科学与工程学院,天津300350

出　　处：《复合材料学报》2021年第8期2666-2675,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51971242);大学生创新创业训练计划项目(201910059036)。

摘　　要：采用原位化学气相沉积、短时球磨和填加造孔剂法相结合的工艺制备了碳纳米管(CNTs)/Al复合泡沫,研究了其在压缩-压缩循环载荷下的力学性能及失效机制。结果表明,CNTs/Al复合泡沫的应变-循环次数曲线经历线弹性、应变硬化及应变快速增长三个阶段。不同于泡沫铝的逐层坍塌变形失效模式,CNTs/Al复合泡沫疲劳失效的主要原因是大量剪切变形带的形成,试样出现快速的塑性变形。此外,CNTs含量为2.5wt%、孔隙率为60%的复合泡沫试样的疲劳强度相比于泡沫铝提高了92%。CNTs的均匀分布及增强相与基体材料之间良好的界面结合性保证了疲劳载荷能够以剪切力的形式从基体传递到CNTs上,使其充分发挥自身高强度、高韧性的特点,进而提高了疲劳性能。Carbon nanotubes(CNTs) reinforced Al matrix composites were fabricated by spacer-holder method,including in-situ chemical vapor deposition and ball milling process. The mechanical properties and failure mechanisms of the CNTs/Al composite foams were investigated under compression-compression cyclic loading. The results show that the strain-number of cycle curves of the CNTs/Al composite foams is composed of three stages: elastic stage,strain hardening stage and rapid accumulation stage,which is similar to Al foams. Different from Al foams’ deformation of layer-by-layer,the main failure modes of CNTs/Al composite foams are the collapse of pores within significant shear deformation bands under fatigue loading and rapid plastic deformation of the specimens. In addition,the fatigue strength of the CNTs/Al composite foams with CNTs content of 2.5 wt% and porosity of 60% increases by 92% than Al foams. The CNTs/Al composites exhibit uniform CNTs distribution and good interfacial bonding between CNTs and Al matrix,which guarantees the effective transmission of fatigue loading in the way of shear stress from Al matrix to CNTs,so that the CNTs can give full play to the characteristics of high strength and high toughness,and then improve the fatigue performance.

关 键 词：泡沫铝 碳纳米管 压缩疲劳 失效机制 增强机制 

分 类 号：TB331[一般工业技术—材料科学与工程] TB333