J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (9): 2017-2026.DOI: 10.1016/j.jmst.2019.05.017

• Orginal Article • Previous Articles     Next Articles

Effects of Mg17Al12 second phase particles on twinning-induced recrystallization behavior in Mg-Al-Zn alloys during gradient hot rolling

Zhong-Zheng Jinab, Xiu-Ming Chengb, Min Zhaab*(), Jian Rongb, Hang Zhangb, Jin-Guo Wangb, Cheng Wangb, Zhi-Gang Lib, Hui-Yuan Wangabc*()   

  1. a State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
    b Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Nanling Campus, Jilin University, Changchun 130025, China;
    c International Center of Future Science, Jilin University, Changchun 130012, China
  • Online:2019-09-20 Published:2019-07-26
  • Contact: Zha Min,Wang Hui-Yuan
  • About author:

    1 These authors contributed equally to this work.

Abstract:

This study aims to investigate the promotion effect of twinning-induced nucleation vs the inhibition effect of Mg17Al12 particles pinning for recrystallization, achieved through gradient rolling for Mg-3Al-1Zn (AZ31) and Mg-9Al-1Zn (AZ91) alloys as well as pure Mg. Through gradient rolling, a transition zone from the initial to deformed microstructure undergoing varying thickness reductions was obtained in the same sample, where the evolution of deformation twins and second phase can be examined precisely and continuously. During hot deformation, dynamic recrystallized (DRXed) grains tended to originate from {10$\bar{1}$1}-{10$\bar{1}$2} double twins, whose nucleation was significantly restricted by increasing Al content and hence recrystallization can be rarely triggered in AZ91 alloy. Concurrently, the size and volume fraction of Mg17Al12 particles changed via dissolution and re-precipitation, leading to finer average size and higher volume fraction, which produced stronger pinning effect and hindered dynamic recrystallization significantly. The current study provides insights into the mechanisms responsible for dynamic recrystallization behavior during hot rolling in Mg-Al-Zn alloys.

Key words: Magnesium alloys, Microstructure, Dynamic recrystallization, Texture