Evolution of the metallurgical properties of Ti-6Al-4V, produced with different laser processing parameters, at constant energy density in selective laser melting

The improvement of the density with functional microstructure is still a challenge in the Selective Laser Melting process considering the laser processing parameters. In this study, the pore formation mechanisms and microstructural changes caused by the effects of laser power and track overlap during the manufacturing process in selective laser melting were examined. Laser power played a crucial role in the geometry and quantity of keyhole pore formation and thus in improving density and quality. In contrast, a slightly higher track overlap led to a significant reduction in porosity, resulting in the production of fully dense samples of a Ti-6Al-4V alloy. The gradual variations in the solid-state phase transformation architecture occurred with variations in laser power and track overlap due to the use of different thermal mechanisms. The associated scanning speeds also significantly affected the microstructural architectures in some states. The melt pool dynamics and thermal properties that influenced the metallurgical properties of the samples are analyzed and interpreted. The analysis of the presented consequences can help the engineers to produce high density products together with functionally graded materials.