摘要
通过真空自耗熔炼、锻造、退火等工艺制备得到不同含量原位自生Ti C、Ti B,以及Ti C+Ti B(体积比1∶1)钛基复合材料,研究了其显微组织、室温和高温(300℃)拉伸性能以及室温压缩性能,并分析了室温拉伸时Ti C和Ti B强化作用之间的耦合关系。结果表明:复合材料的基体组织为变形α组织,Ti C呈细小等轴状和略微粗大椭球状,Ti B呈短纤维状;当增强体总体积分数相同时,Ti C+Ti B的强化效果高于Ti C或Ti B的,且随着增强体体积分数的提高而增强,但复合材料的塑性明显下降;复合材料室温拉伸断裂方式主要是增强体的承载断裂,而高温拉伸时的断裂方式包括增强体的承载断裂和部分Ti B短纤维与基体的脱黏;室温拉伸时,Ti C与Ti B的强化作用与细晶强化作用间满足耦合系数1.5的叠加关系。
The different contents of in-situ synthesized Ti C,Ti B and Ti C+Ti B(volume proportion of 1∶1)/Ti titanium matrix composites were prepared by vacuum consumable melting,forging and annealing process,and the microstructure,tensile properties at room temperature and high temperature(300℃)and compression properties at room temperature were studied.The coupling relationship between the strengthening effects of Ti C and Ti B during stretching at room temperature was analyzed.The results show that the matrix structure of composites was deformedαstructure;Ti C presented fine equiaxed shape and slightly thick ellipsoidal shape,and Ti B presented short fiber shape.When the total volume fraction of reinforcements was fixed,the strengthening effect of Ti C and Ti B was higher than that of Ti C or Ti B,and increased with the increase of volume fraction of reinforcements;however,the plasticity of composites decreased obviously.The main tensile fracture mode of composites at room temperature was bearing failure of reinforcements,while the fracture mode at high temperature included bearing failure of reinforcements and debonding of some Ti B short fibers with matrix.The relationship of strengthening effects between Ti C and Ti B reinforcements and fine-grain met the superposition of coupling coefficient of 1.5 during stretching at room temperature.
作者
徐欢
郭相龙
吕维洁(指导)
XU Huan;GUO Xianglong;L Weijie(State Key Laboratory of Metal Matrix Composites,Shanghai Jiaotong University,Shanghai 200240,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2020年第1期62-67,73,共7页
Materials For Mechanical Engineering
基金
国家自然科学基金资助项目(51371114).
