Influence of Process Parameters on Temperature Field, Microstructure, and Mechanical Properties of FSW Thick Aluminum Alloy 2219

The fuel tank of the heavy launch vehicle is made of high-strength aluminum alloy 2219 with a thickness of 18 mm. The assembly process is mainly based on friction stir welding (FSW) technology. The increase in tank thickness intensifies the non-uniformity of temperature distribution and then affects the microstructure and mechanical properties of different areas of the joint. At present, the research on the influence of process parameters on temperature field, microstructure, and mechanical properties of FSW thick aluminum alloy 2219 plate is still blank. In this paper, temperature measurement experiments of FSW 18-mm-thick aluminum alloy 2219 are conducted by using thermocouple temperature measurement method. Then, combined with the microstructure observation and tensile test of welded joints, the thermal cycle temperature, microstructure, and mechanical properties of the joints under different rotation speeds ( n ), welding speeds ( v ) and pitch ratio ( n / v ) are explored. The research provides reference for selection of welding process parameters to ensure high quality of FSW thick aluminum alloy 2219 plate.