摘要
变形铝合金中存在大量弥散的强化相,在其周围将产生较大的残余应力。残余应力的存在,对合金构件的强度、疲劳寿命、结构尺寸稳定性以及抗应力腐蚀等性都有很大的影响。会聚束电子衍射图中的高阶带反射线对晶格参数变化敏感,残余应力的存在可使高阶带反射线发生位移或偏转,可以用来测量材料微区的残余应力。利用会聚束电子衍射技术研究时效处理后Al12Zn2.4Mg1.1Cu合金的残余应力。研究结果表明:Al12Zn2.4Mg1.1Cu铝合金中析出相附近的基体中存在较大的残余应力,残余应力随距析出相距离的增加而减少,距离析出相5 nm、45 nm和85 nm处的残余应力分别为210 MPa、202 MPa和145 MPa。
Lost of dispersed strengthening phases exist in wrought aluminum alloy. Meanwhile, the residual strain fields are generated around the precipitated phase. Residual strain fields are detrimental to the strength, fatigue life, dimensional stability, stress corrosion resistance, and other material performances. The position of high order Laue zone（HOLZ） lines in the convergent beam electron diffraction（CBED） pattern is very sensitive to the changes in lattice parameters. According to the HOLZ line shifts and rotation, the residual strain of composite can be measured. Convergent beam electron diffraction technique is employed to explore the residual stress in the matrix of the All2Zn2.4Mgl.ICu alloy after heat treatment. The analytical results demonstrated that there existed obvious residual strain nearby precipitations, the residual stress is reduced as the distance increase in precipitation relative to the distance it could reach 210 MPa at the distance of 5 nm, away from the interface at the 45 nm and 85 nm, respectively, 202 MPa and 145 MPa.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第2期54-58,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(10962005)
关键词
会聚束电子衍射
残余应力
铝合金
Convergent beam electron diffraction Residual stress Aluminium alloy
