Geometric Size Prediction and Microstructure Evolution of Laser-Cladded AlSiTiNi-WC Coating

In this study, a novel 3D finite element model is introduced to effectively simulate the temperature changes in the molten pool, the coating geometry, and the microstructure evolution of AlSiTiNi-WC coatings. To account for the distinct thermal properties of AlSiTiNi-WC powder and AlSiTiNi-WC alloy, a thermal property calculation is employed, resulting in enhanced accuracy of the simulation outcomes. The utilization of the 3D Gaussian heat source model enables the identification of both the coating area and the non-coating area through the implementation of a temperature discrimination mechanism. This approach provides a more visually comprehensive representation of the variations in the coating geometry. The effect of various laser process parameters on the geometric dimensions of the coating was investigated through the utilization of an improved finite element method, which involved simulating the temperature dispersion of the molten pool. The outcomes of the simulation align well with the experimental findings. The temperature field simulation results were utilized to investigate the temperature gradient ( \(G\) $G$ ) and solidification rate ( \(R\) $R$ ) of AlSiTiNi-WC coating. The objective was to examine the connection between the cooling rate ( \(G*R\) $G\ast R$ ) and the resulting microstructure, considering various laser process parameters. In contrast, the scanning speed exerts a more significant impact on the microstructure, resulting in a more pronounced variation in grain size and a more vigorous progression of the microstructure. Higher scanning speeds and lower power settings can yield a finer grain structure.