Numerical Prediction of Melt Pool Size and Defect Appearing During Selective Laser Melting Process of AlSi10Mg at Various Scan Speeds

Abstract

AbstractAdditive manufacturing consists of producing a metallic part by adding material layer by layer, in a single step without specific tooling or material waste. It offers several advantages for both research and industrial sectors. However, as a newly born technology, its main limit is the poor understanding of the process parameters effects on the parts quality. In fact, an improperly chosen parameter could generate defects such as lack of fusion, balling and keyholes during the selective laser melting process. Such defects have a direct relation to the melt pool geometry and can be predicted through several correlations from the literature. This study presents, through a series of numerical simulations of a single track, developed on Ansys Additive©, an investigation of the effect of the scan speed on the melt pool size and, thus, predicting the defect appearing at a fixed laser power. The evolution of the melt pool depth, width and length is depicted at constant laser speed and power. Moreover, the melt pool size is evaluated for a wide range of scan speeds. Results are validated with experimental values from the literature, and show that slow scan speeds generate keyholes and high speeds could generate balling defects.KeywordsSelective laser meltingScan speedMelt pool sizeDefect predictionNumerical simulationAdditive manufacturing