Annealing of a magnesium alloy AZ31 after interrupted cold deformation

作者：Yang, Xuyue^*; Okabe, Yasumasa; Miura, Hiromi; Sakai, Taku

来源：Materials and Design, 2012, 36: 626-632.

DOI：10.1016/j.matdes.2011.12.001

• Non-ferrous metals and alloys
• Heat treatments
• Microstructure

The isothermal annealing behaviors of a magnesium alloy AZ31, deformed by multi-directional forging (MDF) at ambient temperature to cumulative strains ranging from 0.2 to 1.5, was investigated at 473 K. The deformed microstructure is characterized by several types of twins formed in various directions during MDF and their intersections with one another. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) plots of X-rex-t curves are approximated by a linear relationship with an exponent of 2.6 at early stages of annealing irrespective of prior strains, but always break at long times, leading to lower values of the exponent. The non-linear JMAK plots may result from the inhomogeneity of deformed microstructures. The annealing process is composed of new grain formation at the intersections and subsequent large-distance migration of their boundaries, that is discontinuous static recrystallization (dSRX). The annealing characteristics of the cold-deformed Mg alloy are discussed comparing with the contrastive ones of the hot-deformed alloy.

• 出版日期2012-4
• 单位中南大学