Microstructure and mechanical properties of wrought magnesium
alloy AZ31B welded by laser-TIG hybrid①
alloy AZ31B welded by laser-TIG hybrid①
(Department of Materials Engineering,
State Key Laboratory of Material Surface Modification by Laser, Ion and Electronic Beams,
Dalian University of Technology, Dalian 116024, China)
State Key Laboratory of Material Surface Modification by Laser, Ion and Electronic Beams,
Dalian University of Technology, Dalian 116024, China)
Abstract: The laser-TIG hybrid welding was mainly used to weld the wrought magnesium alloy AZ31B. The technical characteristics of laser-TIG hybrid welding process was investigated and the interactional mechanism between laser and arc was discussed, at the same time the microstructure and mechanical properties of the wrought magnesium alloy AZ31B using laser-TIG hybrid welding were analyzed by optical microscope, EPMA, SEM, tensile machine, hardness machine. The experimental results show that the presence of laser beam boosts up the stability of the arc during high speed welding and augments the penetration of weld; the crystal grains of magnesium alloy weld are fine without porosity and cracks in the best welding criterion and the microstructure of HAZ does not become coarse obviously. The elements profile analysis
reveals that Mg content in the weld is lower than that of the base metal, but Al content is higher slightly. Under this experimental condition, the wrought magnesium alloy AZ31B joint can be achieved using laser-TIG hybrid process and the tensile strength of the joint is equivalent to that of the base metal.
reveals that Mg content in the weld is lower than that of the base metal, but Al content is higher slightly. Under this experimental condition, the wrought magnesium alloy AZ31B joint can be achieved using laser-TIG hybrid process and the tensile strength of the joint is equivalent to that of the base metal.
Key words: wrought magnesium alloy AZ31B; laser-TIG hybrid welding; weld