Closed-Loop PID Temperature Control of Additive Friction Stir Deposition

Abstract

Additive friction stir deposition (AFSD), a derivative technology of friction stir welding (FSW), is now rapidly growing in industries that require bulk additive manufacturing. For mass adoption to occur, deposition consistency and quality along with thermal inputs and their impacts need to be better understood and improved. In both AFSD and FSW, it has been demonstrated that properties of depositions or welds vary along their length in response to in-process temperatures. Research using temperature control to maintain weld temperatures in FSW has been performed for some years now with significant results in both quality and reliability, but this technology is just starting to be applied toward AFSD. This work describes the implementation of a temperature control method that was proven successful in FSW to AFSD. It demonstrates the accuracy achievable using that method for AA 7050 T7451 compares the controlled results against a fixed RPM deposition, reviews results of temperature control over multi-pass AFSD, and outlines future work for AFSD involving temperature control.KeywordsAFSDAdditive friction stir depositionTemperature controlPID control