Al-Zn对称成分失稳分解合金的不连续析出转变  

Discontinuous Precipitation of Spinodal Al-Zn Alloy with Symmetrical Composition

作　　者：王大鹏[1] 郝士明[1] 董丹阳[1] 赵刚[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《东北大学学报（自然科学版）》2003年第5期467-470,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(59971015)

摘　　要：通过显微组织和X射线衍射分析,确定了Al Zn对称成分合金在固溶处理成fcc结构单相组织后,在277℃以下发生的不连续析出转变产物形态和转变机制特征·明确了在转变的孕育期内,固溶体发生了失稳分解及随后的连续粗化;不连续析出产物为fcc结构Al基固溶体(α)和hcp结构Zn基固溶体(β)构成的片层状组织,转变的形核位置与温度有关,在200℃以下以沿晶界形核为主;转变的动力学符合Avrami方程关系,Avrami指数为2·?Through microstructure observation and Xray diffraction analysis, characteristic of transformation mechanics of discontinuous precipitation in AlZn alloy with symmetrical composition under 277?℃ were investigated after attaining its single phase microstructure by solution treatment. It is found that spinodal decomposition and subsequent continuous coarsening occur during the incubation period. The discontinuous precipitation shows lamellar microstructure composed of Albased solid solution (α) with f.c.c. structure and Znbased solid solution (β) with h.c.p. structure. The nucleation site depends on the transformation temperature and the cardinal nucleation sites take place along the grain boundaries. The transformation dynamics follows the relationship of Avrami Equation, whose exponent is 2.

关 键 词：AL-ZN合金 对称成分 等体积分数 失稳分解 不连续析出 转变动力学 Avrami方程 

分 类 号：TG146[一般工业技术—材料科学与工程] TG113.12[金属学及工艺—金属材料]