ZA40合金过饱和固溶体胞状分解

摘要

The cellular decomposition of supersaturated soli d solution α′s in Zn-A140 alloy was studies by Differental Scanning Calorim etry (DSC) and Transmission Electron Microscopy (TEM). The results show that α ′s would decompose to form the cellular structure by discontinuous decomposit ion mechanism. The activation energy for decomposition of α′s is 78.79kJ/m o l. The diffusion of zinc is the rate determining process for decomposition of α ′s and the growth of the cellular colonies is controlled by boundary diffusio n. The migration of the boundary occurred during the growth of the cellular col onies and the lamella equilibrium structure (α+η) would form at last.%利用差热扫描量热仪（DSC）及透射电子显微镜（TEM ）研究了Zn-Al40合金过饱和固溶体α′s在连续加热及等温时效过程中的不连续分解。 结果表明：过饱和固溶体α′s在连续加热及等温时效过程中将发生分解，并通过不连续 分解机制形成胞状组织，其反应激活能为78.79kJ/mol。锌的扩散速度决定过饱和固溶体α ′s的胞状分解速度，且胞状组织的生长受晶界扩散控制。胞状组织在生长过程中发生晶 界迁移，最终形成α-η-Zn片层相间的组织。