Ti-15s/TiCP复合材料的拉伸断裂过程  

Tensile Failure Mechanism in Ti-15S/TiCp Reinforced Composite

作　　者：张廷杰[1] 曾泉浦[1] 毛小南[1] 陈绍楷[1] 

机构地区：[1]西北有色金属研究院

出　　处：《稀有金属材料与工程》1997年第5期18-22,共5页Rare Metal Materials and Engineering

摘　　要：用金相、ＳＥＭ和ＴＥＭ研究了ＰＴＭＰ技术制备的含１０％体积分数粒子的Ｔｉ—１５Ｓ／ＴｉＣ颗粒强化复合材料的显微组织、拉伸断口及拉断试样纵向显微组织特征。原始复合棒料是等轴晶组织，增强体ＴｉＣ粒子随机分布于基体中，增强体和基体界面连接良好，尺寸较大的ＴｉＣ粒子中有孔洞存在。在拉伸过程中，由于ＴｉＣ粒子是主要的承载体而首先断裂，粒子裂纹快速扩展到基体造成复合体快速断裂。尺寸较大的ＴｉＣ粒子中的原有孔洞，加速了粒子断裂和复合体断裂过程。粒子尺寸不均和粒子分布不均匀的复合体，其拉伸延性较低。大量断口观察和显微组织分析均末发现粒子裂纹沿粒子与基体界面扩展的痕迹，而复合材料的基体都展示出良好的塑性断裂特征，这意味着ＰＴＭＰ技术制备的复合材料界面性质良好，界面反应过程中，粒子中的碳没有或很少进入基体。The microstructures, the microstructural characteristics of longitudinal profile and fracture surfaces of tensile failed samples have been characterized by optical microscopy, SEM and TEM for the Ti-15S alloy containing 10 Vol% TiC, which had been processed via a PTMP route. The as-forged and heat-treated bar have equiaxed granular microstructures. The rein-forcement (TiC particles) is reasonably randomly distributed. The reinforcement and the matrix are very bonded. However,there is porosity within the large TiC particles. During the tensile test, since the reinforcement carries a significant ftaction of the load, the load increases until the fracture strength of the particles and then is followed by failure of the composite. Particulate fracture appears to be annexed by internal prosity. Inhomogeneity of particle size lowers the ductility of the composite.Microstructural examination of numerous mechanically tcsted samples indicates that the particle-crack does not spread around the interface between the TiC particle and the matrix, but propagates into the matrix. For all fracture surfaces observed in this work the matrix undergoes ductile failure. There is a negligible diffusing of C into the matrix from particles during interfacial reaction.

关 键 词：钛基 复合材料 碳化钛 显微组织 裂纹 拉伸 断裂 

分 类 号：TB333[一般工业技术—材料科学与工程]