Acta Metallurgica Sinica (English Letters) ›› 2017, Vol. 30 ›› Issue (11): 1135-1144.DOI: 10.1007/s40195-017-0654-8

Special Issue: 2016-2017镁合金虚拟专辑

• Orginal Article • Previous Articles    

Microstructure Evolution and Deformation Behavior of AZ31 Magnesium Alloy During Alternate Forward Extrusion

Feng Li1,*(), Yang Liu1, Xubo Li1   

  1. 1 School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China
  • Received:2017-09-20 Revised:2017-09-20 Online:2017-11-20 Published:2018-01-30
  • Contact: Li Feng

Abstract:

The paper presents a new extrusion method, alternate forward extrusion, in which the punch was replaced with double-split structures so as to achieve the grain refinement for material near the interface of double-split structures. The results showed that the unique loading mode made metal flow sequence and behavior significantly changed during alternate forward extrusion. The additional shear deformation produced by the double-split punch structures resulted in a refining effect on the microstructure of the blank, which was then further refined during flow through the die orifice owing to shear deformation. Compared with the conventional extrusion, the recrystallization process in the alternate forward extrusion process produced grains that were smaller and more homogeneous in size. The recrystallization process was more abundant, and the dislocation density was significantly increased. It can be concluded that the alternate forward extrusion process could achieve fine-grained strengthening, which provided technical support and scientific guidance for the engineering application of magnesium alloy extrusion forming technology.

Key words: Magnesium alloy, Alternate forward extrusion, Microstructure evolution, Deformation behavior