摘要
采用改进的分离式Hopkinson拉杆试验装置和新设计的帽形剪切试样,研究了混合盐法制备的TiB_2/2024Al复合材料在不同温度(25,150,300,450℃)下的高应变速率(动态)剪切行为,并观察了复合材料的剪切断口形貌。结果表明:不同温度下,复合材料的动态名义剪切应力-剪切应变曲线相似,变形初期剪切应力随剪切应变的增大而增大,当剪切应变超过一定值时,曲线呈稳态流变特征;随着温度的升高,复合材料的剪切强度降低而断裂应变增大;复合材料剪切断口主要呈金属撕裂棱和韧窝形貌,局部有熔铝带存在,部分TiB_2颗粒上出现裂纹,随着温度的升高,断口中孔洞的数量增加,尺寸增大。
High strain-rate（dynamic）shear behavior at different temperatures（25,150,300,450 ℃）of TiB2/2024 Al composite prepared by mixed salts method was investigated with a newly designed hat-shaped shear specimen by the improved split Hopkinson tension bar testing,and the shear fracture morphology of the composite was analyzed.The results show that the dynamic nominal shear stress-shear strain curves of the composite at different temperatures were similar.At the initial stage of deformation,the shear strength increased with the increase of shear strain,and when the shear strain was larger than a certain value,the curve showed steady-state rheological features.The shear strength of the composite decreased while the fracture strain increased with the increase of temperature.The fracture of the composite mainly showed features of metal tear ridge and dimples,melted aluminum zones appeared in some local regions,and cracks existed in some TiB2 particles.The size and quantity of voids on facture both increased with the increasing testing temperature.
作者
周平
郭伟国
李艳萍
ZHOU Ping;GUO Weiguo;LI Yanping(School of Aeronautics,Northwestern Polytechnical University,Xi＇an 710072,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2018年第9期61-64,共4页
Materials For Mechanical Engineering
基金
国家自然科学基金资助项目(11572261
11372255)
