Analytical Modeling of Selective Laser-Melting Temperature of AlSi10Mg Alloy

Selective laser melting (SLM) plays a critical role in additive manufacturing, particularly in the fabrication of complex high-precision components. This study selects the AlSi10Mg alloy for its extensive use in the aerospace and automotive industries, which require lightweight structures with superior thermal and mechanical properties. The thermal load induces residual tensile stress, leading to a decline in the geometric accuracy of the workpiece and causing cracks that reduce the fatigue life of the alloy. The rapid movement of the laser heat source during the material formation creates a localized and inhomogeneous temperature field in the powder bed. Significant temperature gradients are generated, resulting in thermal stresses and distortions within the part, affecting the quality of the molding. Therefore, understanding the effects of processing parameters and scanning strategies on the temperature field in SLM is crucial. To address these issues, this study proposes a multiscale method for predicting the complex transient temperature field during the manufacturing process based on the heat-conduction equation. Considering the influence of temperature on the material properties, a temperature-prediction model for discontinuous scanning paths in SLM and a temperature field-calculation model for irregular scanning paths are developed. The models are validated using finite-element results and are in excellent agreement. The analytical model is then used to investigate the effects of the laser power, scanning speed, and scanning spacing on the temperature distribution. The results reveal that the peak temperature decreases exponentially with increasing scanning speed and increases linearly with increasing laser power. In addition, with increasing scanning spacing, the peak temperature of the adjacent tracks near the observation point decreases linearly. These findings are critical for optimizing the SLM-process parameters and improving the material-forming quality.