Mechanical properties of welded joints in vertical-up variable polarity plasma arc welding of 2219 aluminum alloy
(1.黑龙江省哈尔滨市哈尔滨工业大学现代焊接生产技术国家重点实验室2.School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200030, China3.State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China)
Abstract: The mechanical properties of the 2219 aluminum alloy welded joints by vertical-up variant polarity plasma arc welding (VPPAW) with keyhole were analyzed. The tensile strength of welded joints can reach 55% of that of base metal. The microstructure of weld joints was studied to explain the mechanical properties of the weld. The results show that the intensity of weld center is less than that of HAZ, and the intensity of weld center is the worst. So an advanced welding procedures is presented to reduce the heat input and increase the welding speed. The results in this procedures show that the tensile strength of welded joints reaches more than 60% of that of the parent metal, and the specific elongation does not descend.
Key words: 2219 aluminum alloy； variable polarity plasma arc welding； mechanical property； microstructure