Rapid prediction of substrate deformation in laser deposition repair process for Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy based on the inherent strain method

Abstract

Rapid prediction of substrate deformation for thin-wall component repairing of Ti–6.5Al–3.5Mo–1.5Zr–0.3Si alloy by laser deposition technology was investigated for the optimization of the laser scanning strategy and improvement of the repair efficiency. A local model based on thermo elastic-plastic theory was established for inherent strain extraction. On this basis, an inherent strain model was built to simulate the deformation of long side and short side reciprocating deposition. Prediction accuracy and computational efficiency of the proposed inherent strain model were compared with the classic thermo elastic-plastic predictive and the experimental results. The results show that prediction error of the inherent strain model was 7.35 %. Though lower than the classic thermo elastic-plastic prediction (2.42 %), calculation time was reduced to 18 %∼41 % of that based on the thermo elastic-plastic model. Moreover, substrate distortion was well controlled when the scanning path was parallel to the fixed constraint surface since the residual stress was smaller.