Study on Microstructures and Mechanical Properties of TA23 Alloy Welded Joints by Different Welding Processes

TA23 alloy sheets were welded by CMT, TIG and EBW, and the study on the microstructures and mechanical properties of the welded joints were carried out. The results showed that the welding heat input directly influenced the size of grain and the width of the joints; The size of grain by TIG process was the largest, followed by that by CMT, while the size of grain by EBW was the smallest; The width of the joint by EBW was 5 mm, the width by CMT 7 mm, and the width by TIG 14 mm; Microstructures of welded seams created by the three welding processes mainly consisted of martensite α, lamellar α and residual β phases, while the microstructures of HAZ was between those of welded seams and base metal; The micro-hardnesses and tensile strengths of the welded seams from the three processes were higher than those of the base metal, of which the micro-hardness of the EBW joint was the highest and the tensile strength of TIG was the highest, while the properties of CMT joint are between those of TIG and EBW.