Numerical analysis of residual stress evolution of AlSi10Mg manufactured by selective laser melting

• Published in: Optik (Stuttgart) Vol. 137; pp. 65 - 78
• Main Authors: Wu, Jiaojiao, Wang, Linzhi, An, Xuguang
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.05.2017
• Subjects: AlSi10Mg alloy; Laser exposure time; Numerical simulation; Residual stress; Selective laser melting; Numerical simulation; Laser exposure time; Selective laser melting; AlSi10Mg alloy; Residual stress
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2017.02.060

In selective laser melting (SLM) process, severe temperature gradients produce large residual stresses, which leading to part distortion and bad performance of alloy products. At present, numerical simulations are widely used to study temperature and residual stress filed within materials, nevertheless, the residual stress prediction of alloys in the way of discontinuous laser scanning is rare to be carried out for SLM manufacturing. This study is aim to establish proper numerical models to investigate residual stress evolution of AlSi10Mg alloy in point exposure SLM process. Firstly, a concept of moving equivalent heat source has been developed to act on powder bed’s surfaces to simulate corresponding SLM process. Then, local temperature field within alloy parts are obtained by the built heat transfer model. In next, the derived temperature results are imported into the built solid mechanical model as a predefined field to analyze residual stress field of AlSi10Mg alloy parts. The consequence of numerical analysis is that, with laser exposure time increasing, the residual stress within alloy parts are gradually rising up. At last, residual stress of AlSi10Mg alloy parts are measured through experiments. The experimental data coincide with simulated results very well, which validates the reliability of established numerical models on residual stress evaluation of alloys during discontinuous laser scanning in SLM manufacture field.