强变形诱导形成的Al-Cu合金过饱和固溶体在继续变形时的再析出行为

利用X射线衍射分析及透射电镜观察,研究含析出相的Al-Cu合金经多向压缩变形诱导析出相回溶后形成的过饱和固溶体在继续变形过程中的再析出行为.结果表明:Al-Cu合金中的析出相经强塑性变形诱导形成过饱和固溶体;在继续变形过程中,当变形量增大到一定程度后过饱和固溶体将分解出析出相,此时析出相的析出顺序与常规态过饱和固溶体分解的析出顺序不同,过渡相析出被抑制,直接形成稳定相.当过饱和固溶体在继续变形过程中析出稳定相后,稳定相的回溶和再析出交替进行.

Re-precipitate behavior of supersaturated solid solution of Al-Cu alloy caused by severe plastic deformation during subsequent deformation

The supersaturated solid solution is formed by re-dissolution of precipitated phases during multi-axial compression in aged Al-Cu alloy. The re-precipitation behavior of strain-induced supersaturated solid solution during subsequent deformation was investigated by X-ray diffraction and transmission electron microscopy. The results show that new precipitated phases will precipitate from the strain-induced solid solution when the total strain increases to a certain degree during subsequent deformation; and the precipitation sequence is directly forming stable phases instead of metastable phases, which is different from that of the conventional supersaturated solid solution formed by heat treatment. After that, the stable phases will re-dissolve and re-precipitate alternately.