Parametric optimization of selective laser melting for forming Ti6Al4V samples by Taguchi method

In this study, a selective laser melting experiment was carried out with Ti6Al4V alloy powders. To produce samples with maximum density, selective laser melting parameters of laser power, scanning speed, powder thickness, hatching space and scanning strategy were carefully selected. As a statistical design of experimental technique, the Taguchi method was used to optimize the selected parameters. The results were analyzed using analyses of variance (ANOVA) and the signal-to-noise (S/N) ratios by design-expert software for the optimal parameters, and a regression model was established. The regression equation revealed a linear relationship among the density, laser power, scanning speed, powder thickness and scanning strategy. From the experiments, sample with density higher than 95% was obtained. The microstructure of obtained sample was mainly composed of acicular martensite, α phase and β phase. The micro-hardness was 492 HV0.2.

► The orthogonal experiment is designed on selective laser melting. ► To get the optimum process parameters. ► To get a selective laser melting (SLM) sample with the density higher than 95%. ► The sample, with small grain size, has a micro-hardness higher than as-cast.