Microstructure and mechanical properties of Mg-Li alloy after TIG welding

• Published in: Transactions of Nonferrous Metals Society of China Vol. 21; no. 3; pp. 477 - 481
• Main Authors: LIU, Xu-he, GU, Shi-hai, WU, Rui-zhi, LENG, Xue-song, YAN, Jiu-chun, ZHANG, Mi-lin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-03-2011
• Subjects: Alloy plating; Base metal; Enrichment; Grain boundaries; Heat affected zone; Mechanical properties; Mg-Li alloy; Microstructure; segregation; TIG welding; Welded joints; Mg-Li alloy; TIG welding; microstructure; segregation; mechanical properties
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(11)60739-5

Tungsten inert gas weld was carried out on super-light magnesium-lithium alloy plates with a thickness of 2 mm, using argon gas as a protecting atmosphere. The microstructure and mechanical properties of the welded joints were investigated. The results indicate that the microstructure in the fusion zone is fine, and the microstructure in the heat-affected zone is coarser than the parent metal. The tensile strength of the welded joint is about 84% that of the parent metal. The fracture occurs in a mixed type of toughness and brittleness in the heat-affected zone. During the welding process, aluminum and cerium are enriched at grain boundaries in the fusion zone.