Microstructure and Mechanical Properties of Rapidly Cooled Friction Stir Welded Ti-6Al-4V Alloys

作者：Liu, Zhenlei; Wang, Yue^*; Yang, Kang; Yan, Dejun

来源：Journal of Materials Engineering and Performance, 2018, 27(8): 4244-4252.

DOI：10.1007/s11665-018-3491-7

• cooling liquid nitrogen
• friction stir welding
• mechanical properties
• microstructure
• Ti-6Al-4V alloy

Two mm-thick Ti-6Al-4V alloy plates were friction stir butt welded under natural- and rapid-cooling conditions. The microstructures and mechanical properties of joints were investigated and compared. The rapid cooling via spraying cooling liquid nitrogen on the plate top surface was beneficial to obtaining a narrower cross section and finer and more uniform grains in the stir zone than those obtained by natural cooling. Joint tensile strength of 1021 MPa and elongation of 1.88% under the rapid-cooling condition respectively reached 102.7 and 150.4% of those under the natural-cooling condition, respectively. The uniform-and-compact equiaxed grains led to equiaxed dimples on the fracture surface, which demonstrated a ductile fracture of the welding joints.

• 出版日期2018-8
• 单位沈阳航空航天大学