中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 12 No. 5 October 2002 |
n zone in SPD
(1. College of Mechanical and Electrical Engineering, University of Petroleum(Huadong), Dongying 257061, China;
2. Key Laboratory of Liquid Structure and Heredity of Materials,
Ministry of Education, Shandong University, Ji′nan 250061, China;
3. College of Resource and Environment Engineering,
East China University of Science and Technology, Shanghai 200237, China)
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.
Key words: Zn-Al alloy; superplasticity; phase boundary sliding; diffusion-solution zone(DSZ)