Deformation prediction of functionally graded materials in laser directional energy deposition using forward-inverse calibration of the inherent strain in multi-scanning directions

Abstract

This paper presents the study of the residual deformation of functional gradient materials (FGMs) constructed by laser directed energy deposition (L-DED) and proposes a forward and reverse framework for inherent strain calibration, considering the effect of scan directions. First, the inherent strain and the corresponding residual deformation in the scanning strategies with the 0°, 45°, and 90° directions are calculated from the multi-scale model of the forward process, respectively. Then the inherent strain is calibrated inversely using the pattern search method based on the residual deformation of experiments by L-DED. The final inherent strain calibrated in the direction of 0° can be achieved through the rotation matrix and averaging. Finally, the final calibrated inherent strain is applied to the model of the rotational scanning strategy. The predicted trend of the residual deformation is highly consistent with the experiments in the verification stage. This work can provide a reference for the prediction of the residual deformation of FGMs.