Hot Deformation Characteristics and Processing Map Analysis of Pre-Forged AZ80 Magnesium Alloy
Abstract
The hot deformation behavior of pre-forged AZ80 magnesium alloy is investigated by the isothermal compression tests at temperatures of 523-683 K and strain rates of 0.0001-0.1 s−1, and analyzed by the processing maps for guiding isothermal die forging. Flow localization and even cracking occurs at low temperatures and high strain rates, where shear deformation degree shows a positive correlation with the ξ (ε ˙) value. Two stability regions with high efficiency is found out by the processing maps. At common stability region with high temperatures and low strain rates, peak power dissipation efficiency does not represent optimum deformation condition as reported in other materials. A Z parameter criterion is introduced for parameters optimization. javascript:void(0); a new stability domain of 523-590 K and 0.0001-0.01 s−1 is observed, which is typical for fine microstructure composed of equiaxed clean α-Mg grains and big particles both about 1 µm (573 K/0.01 s−1). Super plasticity is speculated to occur at that condition.
- Publication:
-
Metals and Materials International
- Pub Date:
- May 2021
- DOI:
- 10.1007/s12540-019-00452-7
- Bibcode:
- 2021MMI....27.1252H
- Keywords:
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- AZ80 magnesium alloy;
- Processing map;
- Isothermal forging;
- DRX;
- PSN