Effects of Li addition on the microstructure and mechanical properties of Mg–3Zn–1Sn–0.4Mn based alloys

• Published in: Journal of alloys and compounds 2013-07, Vol.564, p.130-137
• Main Authors: Son, Hyeon-Taek, Kim, Yong-Ho, Kim, Dae-Won, Kim, Jung-Han, Yu, Hyo-Sang
• Format: Article
• Language: English
• Subjects: Alloys; Applied sciences; Cross-disciplinary physics: materials science; rheology; Elasticity. Plasticity; Exact sciences and technology; Extrusion; Intermetallic compounds; Intermetallics; Magnesium base alloys; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Mechanical property; Metals. Metallurgy; Mg–Li alloy; Microstructure; Other heat and thermomechanical treatments; Physics; Sn addition; Surface layer; Texture; Tin base alloys; Treatment of materials and its effects on microstructure and properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.02.157

•Mg–xLi–3Zn–1Sn–0.4Mn alloys were melted and extruded at 200°C.•Li addition resulted in the formation of MgLi2Sn intermetallic compound.•Li addition resulted in the development of the random texture.•By Li addition, the ductility was significantly increased.•Sn addition resulted in the improvement of strength. In this work, Mg–3wt%Zn–1wt%Sn–0.4wt%Mn alloys with different Li addition (5, 8 and 11wt%) were melted and extruded at 200°C. Effects of Li addition on microstructure and mechanical properties of as-cast and as-extruded Mg–xLi–3Zn–1Sn–0.4Mn alloys were investigated. Li addition to Mg–3Zn–1Sn–0.4Mn based alloy resulted in the formation of MgLi2Sn intermetallic compound. By Li addition from 5wt% to 8 and 11wt%, the ductility was significantly increased from 18.1% to 30.9% and 49.3% at room temperature due to transformation from HCP to BCC crystal structure and formation of a weaker basal texture of the α-Mg phase region. The ultimate tensile strength (UTS) was decreased from 252.0, 201.1 and 148.7MPa as Li content increased from 5 to 8 and 11wt%. On the other hand, the tensile strength of Sn containing alloys was remarkably increased compared to the alloys without Sn addition due to the presence of the fine MgLi2Sn intermetallic compounds.