A Hybrid Thermal Assisted Friction Stir Welding Approach for PMMA Sheets

The widespread application of thermoplastic polymers in different aspects of industries has motivated researchers and companies to improve and upgrade their forming, joining and assembling processes to overcome their limitations. One of the newest joining methods of thermoplastics is friction stir welding which is based on frictional heat generated through contact between a rotating tool and the workpiece. A hybrid thermal assisted friction stir welding approach was proposed in this study for two Poly methyl methacrylate sheets. In this method, the stationary shoe was heated up to the specified temperature and then the FSW tool was gradually plunged toward the clamped sheets. The effects of different process parameters such as rotational and traverse speeds and the heater temperature on the mechanical properties of the joints were studied. Results showed that applying the optimum rotational speeds of 1600 rpm and highest traverse speeds of 12.5 mm/min with the stationary shoe heats up to 70% of base polymer melting temperature which leads to the highest joint performance with strength equal to 95% of PMMA strength.