Studies on the Joint Characteristics of AA5083 and Polymer Materials by Friction Lap Welding

This study investigates the application of friction stir welding (FSW) to join AA5083 aluminum-magnesium alloy and PA6 polyamide. A full-factorial experimental design was conducted to optimize welding parameters and maximize the joint strength of dissimilar materials. The experiment commenced with surface treatment of the materials, followed by lap welding using a pinless stirring tool at rotational speeds of 1500 to 2100 RPM, welding speeds of 100 to 200 mm/min, a plunge depth of 0.1 mm, and a tool tilt angle of 0 degrees. During the welding process, the temperature variations on the aluminum alloy surface were monitored. Joint performance was evaluated through weld zone microstructural analysis and tensile testing, exploring the relationship between temperature and bonding strength. Results demonstrate that AA5083 and PA6 can be effectively joined. The optimal rotational speed of 1800 RPM and welding speed of 200 mm/min achieved a maximum tensile strength of 6.4 MPa. Surface grinding pretreatment significantly enhanced surface roughness, increasing the bonding area and mechanical strength. High heat input during FSW effectively softened PA6, improving its bonding interface with AA5083 aluminum alloy and further reinforcing joint strength.