ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 27    No. 1    January 2017

Effects of extrusion and heat treatments on microstructure and mechanical properties of Mg-8Zn-1Al-0.5Cu-0.5Mn alloy
Shao-zhen ZHU1,2, Tian-jiao LUO1, Ting-an ZHANG3, Yun-teng LIU4, Yuan-sheng YANG1
(1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
3. Key Laboratory for Ecological Metallurgy of Multi-metallic Mineral, Ministry of Education,
Northeastern University, Shenyang 110819, China;
4. Shandong Key Laboratory for High Strength Lightweight Metallic Materials, Jinan 250014, China
)
Abstract: The effects of extrusion and heat treatments on the microstructure and mechanical properties of Mg-8Zn-1Al-0.5Cu- 0.5Mn magnesium alloy were investigated. Bimodal microstructure is formed in this alloy when it is extruded at 230 and 260 °C, and complete DRX occurs at the extruding temperature of 290 °C. The basal texture of as-extruded alloys is reduced gradually with increasing extrusion temperature due to the larger volume fraction of recrystallized structure at higher temperatures. For the alloy extruded at 290 °C, four different heat treatments routes were investigated. After solution + aging treatments, the grains sizes become larger. Finer and far more densely dispersed precipitates are found in the alloy with solution + double-aging treatments compared with alloy with solution + single-aging treatment. Tensile properties are enhanced remarkably by solution + double-aging treatment with the yield strength, tensile strength and elongation being 298 MPa, 348 MPa and 18%, respectively. This is attributed to the combined effects of fine dynamically recrystallized grains and the uniformly distributed finer precipitates.
Key words: magnesium alloy; extrusion microstructure; texture; heat treatment; mechanical properties
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)