The effect of build direction and geometric optimization in laser powder bed fusion of Inconel 718 structures with internal channels

A laser powder bed fusion (LPBF) strategy was developed for manufacturing small channels with high dimensional accuracy in Inconel 718 structures. Particular attention paid to surface characteristics such as equivalent diameter and shape factor. The inherent quality of external surfaces optimized by a systematic variation the LPBF contour parameters well channel cross-section. mean arithmetic roughness Sa analysed upskin, vertical downskin respect build platform. Simultaneously, effect direction on internal free-shaped investigated diameters from 500 1000 µm orientations horizontal (0°) (90°). significant improvement achieved using an droplet-shaped cross-section that is scaled function inclination. An angular analysis different regions confirms this modified reduces fraction show particularly due inward melting. In combination processing strategy, resulted best properties inclinations below 45°. factor increased 0.4 almost 0.9, i.e., close ideally round shape.