The Effect of Laser Powder Bed Fusion Process on Ti-6Al-4V Powder

Abstract Additive manufacturing with Ti-6Al-4V laser powder bed fusion (L-PBF) processes offers significant advantages for producing high-performance components. Hence, powder reuse strategies are crucial for reducing manufacturing costs and environmental impact, and reliable part properties. This study investigates the influence of L-PBF processing on the properties of virgin, recycled, and spatter Ti-6Al-4V powders. Particle size distribution, morphology, microstructure, chemical composition, and microhardness were determined using a laser particle size analyzer, scanning electron microscopy (SEM), X-ray diffraction (XRD), and microhardness testing. Virgin powder exhibited a narrow size distribution and spherical morphology. Recycled powder showed a slightly broader distribution and increased irregularity, while spatter powder had a significantly broader distribution with large, irregular particles. Microstructural analysis revealed that all powders exhibited an acicular α′ martensite microstructure, while the presence of twins was unique to the virgin powders. The average α′ lath thickness was similar for virgin and spatter powders, with a slightly higher in the recycled powders. XRD confirmed the presence of the α′ phase, and dislocation density was highest in virgin powder and lowest in spatter powder. Microhardness measurements indicated a slight decrease in hardness for recycled powders and a wider range of hardness values for spatter powders compared to virgin powders.