Mechanism for phase boundary sliding and its relevance to diffusion-solution zone in SPD

来源期刊：中国有色金属学报(英文版)2002年第5期

论文作者：石志强 叶以富 李世春 张磊

文章页码：952 - 955

Key words：Zn-Al alloy; superplasticity; phase boundary sliding; diffusion-solution zone(DSZ)

Abstract: The diffusion behavior of Zn/Al interfaces in their powders sintering was investigated with SEM. The results show that Zn-Al eutectoid microstructure can be achieved through their powders sintering, and the diffusion characteristic between Zn and Al is just a demonstration of Kirkendall effect, by which Zn can dissolve into Al and contrarily Al cannot dissolve into Zn. During sintering, a diffusion-solution zone /′ has formed and subsequently transforms into eutectoid microstructure in cooling process. The superplastic deformation mechanism of Zn-Al eutectic alloy is phase boundary sliding which is controlled by diffusion-solution zone α′. If diffusion-solution zone α′ is unsaturated, it will have much more crystal defects and the combination between α′ and β phase is weak, thus the process of phase boundary sliding becomes easily; on the contrary, if the diffusion-solution zone α′ becomes thick and saturated, the sliding will be difficult.