On the Utility of the Thermal-Pseudo Mechanical Model’s Residual Stress Prediction Capability for the Development of Friction Stir Processing

Abstract This paper investigates the thermal-pseudo mechanical (TPM) model’s residual stress prediction capability for its utility in developing friction stir processing (FSP). Specifically, two FSP tests under different processing conditions were conducted, and the corresponding simulations were carried out to verify if the TPM model can predict residual stresses for various tool radii and workpiece materials. The model was successful in predicting residual stresses for one of the tests but failed to work for the other test. Further simulations under different FSP conditions prove that the TPM model works for cast aluminum alloys in addition to wrought aluminum alloys. However, there is only a range of tool radii for which the TPM model is applicable, and the large FSP tool used is the reason for the model’s failure on one of the tests. As a solution, this paper suggests modifications to the TPM model based on calibration to the FSP test temperatures. The calibrated TPM model still cannot predict the effect of the tool radii on the residual stresses; however, the effect on residual stresses due to changes in the process parameters, such as the tool traverse & rotation speeds and the clamping conditions, can be predicted.