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

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 alpha ' martensite microstructure, while the presence of twins was unique to the virgin powders. The average alpha ' lath thickness was similar for virgin and spatter powders, with a slightly higher in the recycled powders. XRD confirmed the presence of the alpha ' 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.