Abstract

Selective laser melting (SLM) is an additive manufacturing (AM) process that gives rise to large thermal gradients and rapid cooling rates that lead to the development of undesirable residual stress and distortion. In this work, a number of different techniques (i.e., x-ray-diffraction, hole-drilling, layer-removal, and contour) were utilized to establish the effect of process parameters on residual stress development during SLM of Ti-6Al-4V. The measurements indicated that higher laser power, slower scan speed, smaller stripe width, reduced substrate overhang, and reduced build plan area each reduce the level of residual stress. In addition, the correlation between microstructure, crystallographic texture, and residual stress were investigated using electron backscatter diffraction (EBSD) and backscatter electron (BSE) imaging. The experimental results from this work provide a quantitative foundation for future simulations of residual stress evolution during SLM and provide an informed understanding of residual stress development that can be used for process planning and improvement.

Biography

Nathan Levkulich is a Research Scientist at UES. He completed his master’s degree in 2017 at Wright State University. His research interests include residual stress and advanced materials characterization.