Study on the thermal-assisted friction stir lap welding for dissimilar materials of 6061-T6 Al alloy and thermoplastic PC

•Thermal-assisted FSLW optimizes the surface appearance.•The maximum tensile strength is approximately 34 MPa, which is obtained at assisted temperature of 120 °C.•The dislocation motion between grains is hindered with thermal assist.•The microstructure structure is more compact and stirring is more sufficient as compared to none thermal assist.