Research of the Impact of SLM Printing Parameters on Residual Deformation Levels in Aluminum Products

Abstract

A significant limitation for application in industry of final products obtained by selective laser fusion technology is the formation of residual stresses due to temperature gradients during the formation of layers, which can lead to undesirable deformations of the product, cracks or tearing off of layers in the printing process. The main method of reducing residual stresses is tempering. However, this method does not always contribute to a complete reduction of residual strains. Another, less studied, method can be accomplished by varying the printing process parameters. This approach is particularly effective when residual stresses are accumulated locally due to the geometric shape of the printed object or due to the peculiarities of their arrangement in the 3D printer chamber. In this paper we study the influence of layer-by-layer synthesis parameters on the level of residual stresses in the products obtained by selective laser fusion technology. The probing hole method using digital image correlation was used to estimate the residual strain level. Based on the test results, the residual stress level was evaluated depending on the printing mode.