Remanufacturing oriented multilayer cladding morphology prediction using a new second order fitting method.

Due to the strong coating properties, laser cladding is widely used in the remanufacturing of scrap metal parts. Nevertheless, the risk of cladding quality assurance is increased by the complex cladding formation pattern of multiple multilayers and the unpredictable cross-sectional morphology. In this study, the coupling law of laser power, scanning speed, and powder feeding speed on the geometry of cladding layer is deeply analyzed, and the process-dimension model of single-track melting layers is established. The complex process of laser cladding and the intrinsic laws of process parameters and cladding morphology are revealed by the model. Furthermore, based on the characteristics of the cross-sectional morphology of the cladding layer, a parabolic fitting model of the cross-sectional profile of a single-track cladding layer and an analytical model of the influence of the planar lap of multiple cladding trajectories on the melting width are proposed. Finally, the cross-sectional profile curves of the multilayer cladding were derived and the prediction of the multilayer cladding geometry was achieved. Validation experimental data for laser cladding with 304 powder showed that the average relative errors of melting height and width between the predicted results and the experimental samples were 5.18% and 1.53%, respectively, indicating that the proposed model can accurately predict the cross-sectional shape of the multilayered laser cladding. This study provides experimental data and theoretical prediction methods for the laser remanufacturing of coating profiles on used parts.