Effect of heat treatment on the superplasticity of magnesium alloys

被引：6

作者：

Vesling F. ^{[1
]}

Ryspaev T. ^{[1
]}

机构：

[1] Institute of Welding and Cutting, Technical University, Clausthal, 36678

来源：

Russian Journal of Non-Ferrous Metals | 2007年 / 48卷 / 01期

关键词：

Structural optimization - Metal castings - Grain size and shape - Heat treatment - Hot pressing - Superplasticity - Strain rate;

D O I：

10.3103/S1067821207010117

中图分类号：

学科分类号：

摘要：

A necessary microstructural condition for the manifestation of the effect of superplasticity in alloys is a small grain size (d < 10 μm). The ingots of commercial magnesium alloys have a very coarse cast structure with d > 100 μm. We have studied the regimes of heat treatment of such materials in AZ91, AE42, QE22, and ZRE1 alloys with a purpose of obtaining a fine-grained structure. The optimum temperature of overaging of quenched magnesium alloys lies between 300 and 350°C. After hot pressing of heat-treated alloys, the average grain size is 6.4 (AZ91), 6.2 (AE42), 1.2 (ZRE1), and 0.7 (QE22) μm. The best characteristics of superplasticity are manifested by the ZRE1 and QE22 alloys with a relative elongation of 750% and strain-rate sensitivity m = 0.75 at T = 420°C and strain rate σ= 3 ×10-4 s-1. Under these conditions, the AZ91 and AE42 alloys have δ ≤ 260% and m = 0.45. © Allerton Press, Inc., 2007.

引用

页码：57 / 62

页数：5