Influence of process parameters on the microstructures, residual stresses and mechanical properties of TA15 titanium alloy fabricated by L-PBF

The fabrication of thin-walled components from titanium alloys like TA15 presents challenges due to their high reactivity, resistance to deformation, and low thermal conductivity. Traditional manufacturing methods often struggle with these complexities, making Laser Powder Bed Fusion (L-PBF) a promising alternative due to its advanced design flexibility and processing capabilities. This study explores the effects of L-PBF process parameters—laser power, scanning speed, inter-layer offset angle, and island size—on the microstructure, defects, residual stress, and mechanical properties of TA15 titanium alloy. We varied the laser power from 250 to 310 W and the scanning speed from 1000 to 1400 mm/s, analyzing their impact on sample density, defect formation, and overall mechanical performance. Our findings highlight that an optimal energy density of 55.6 J/mm³, achieved with a laser power of 280 W and a scanning speed of 1200 mm/s, results in superior forming quality. Microstructural analysis shows the predominance of fine, needle-like α′ martensite with high dislocation density. Increased energy density correlates with smaller martensite plate widths and higher residual stresses. Additionally, a 67° inter-layer offset and reduced island sizes help minimize warpage and enhance surface quality. This research offers critical insights for optimizing L-PBF parameters, aiming to improve the performance and durability of TA15 titanium alloy components in aerospace applications.