Acta Metallurgica Sinica (English Letters) ›› 2019, Vol. 32 ›› Issue (1): 10-22.DOI: 10.1007/s40195-018-0793-6

Special Issue: 2019年镁合金专辑 2019年腐蚀专辑-2

• Orginal Article • Previous Articles     Next Articles

Enhanced Strength and Corrosion Resistance of Mg-2Zn-0.6Zr Alloy with Extrusion

Luan-Xiang Wang1, Ren-Bo Song1(), Chang-Hong Cai1, Jing-Yuan Li1   

  1. 1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2018-05-08 Revised:2018-06-05 Online:2019-01-10 Published:2019-01-18
  • Contact: Song Ren-Bo
  • About author:

    Author brief introduction:Dao-Kui Xu Professor of IMR, CAS, and “Young Merit Scholar” of Corrosion Center in the Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS). He achieved Ph.D. degree from IMR, CAS, in 2008, during which he obtained “Chinese Academy of Sciences-BHP Billiton” Scholarship award, “Shi Changxu” Scholarship award and “Zhu-LiYueHua” Excellent Doctorate Student Scholarship of Chinese Academy of Sciences. He worked as a Research Fellow in ARC Center of Excellence, Design of Light Metals, Department of Materials Engineering, Monash University, Australia (2008.10-2011.10). He published more than 60 peer-reviewed scientific papers, attended 20 invited lectures and holds seven patents. His papers were cited more than 1200 times. His research interests mainly include: (1) fatigue behavior and fracture toughness of light metals, such as Mg, Al and Ti alloys; (2) effects of alloying, heat treatment and thermomechanical processes on the microstructural evolution and mechanical improvement of light metals; (3) corrosion, stress corrosion cracking and corrosion fatigue behavior of lightweight alloys; and (4) design of new lightweight alloys with a good balance of properties in terms of mechanical property and corrosion resistance.

Abstract:

The microstructure, mechanical properties and corrosion behavior of Mg-2Zn-0.6Zr alloy under the as-cast and as-extruded conditions were investigated. Microstructure analysis indicated the remarkable grain refinement by extrusion, as well as notable reductions in volume fraction and size of precipitate phases. As compared with the as-cast alloy, the as-extruded alloy exhibited better mechanical performance, especially in yield strength which was promoted from 51 to 194 MPa. Refined grains, dispersive precipitate phases and texture were thought to be the main factors affecting the improved performance in strength. The electrochemical measurement and immersion test revealed the corrosion rate of Mg-2Zn-0.6Zr alloy by extrusion decreased from 1.68 to 0.32 mm/year. The reasons for the enhanced corrosion resistance were mainly attributed to the decreased volume fraction and Volta potential of the precipitate phases, the refinement of the grain size, as well as the formation of more protective corrosion film.

Key words: Mg-2Zn-0.6Zr, Extrusion, Strength, Corrosion behavior