摘要
Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investigated in detail. The results show that cladding billets with different clad-ratios were fabricated successfully. Si and Mn elements diffused across the bonding interface and formed diffusion layer. With the increase of clad-layer thickness, the interfacial region transforms from semisolid-solid state to liquid-solid state and the diffusion layer increased from 10 to 25 μm. The hardness at interface is higher than that of AA3003 side but lower than that of the other side. The bonding strength increased with the clad-layer thickness, attributing to solution strengthening due to elements diffusion. The cladding billets were extruded into clad pipe by indirect extrusion process after homogenization. The clad pipe remained the interfacial characteristics of as-cast cladding billet and the heredity of clad-ratio during deformation was testified.
采用数值模拟和实验相结合的方法研究了不同包覆率的AA4045/AA3003铝合金包覆铸锭的制备,并对界面处的温度场和组织性能进行了详细分析。结果表明,采用直接水冷铸造法可得到不同包覆率的铸锭,Si和Mn在界面处发生了互扩散并形成扩散层。随着包覆率的增加,两种合金接触时界面区域由半固态-固态转变为液态-固态,界面处硬度由HV 47增加到HV 55,扩散层厚度由10增加到25μm。界面处硬度高于AA3003合金一侧,低于4045合金一侧,这是由元素扩散引起固溶强化造成。均匀化退火后,在包覆铸锭被反向挤压成复合管材的过程中,界面处保持层状结构不变,包覆率在变形过程中的遗传性得到证实。
基金
Project(2015B090926013)supported by the Science and Technology Program of Guangdong Province,China
Project(20170540307)supported by the Natural Science Foundation of Liaoning Province,China
