Effects of Stripe Width on the Porosity and Mechanical Performance of Additively Manufactured Ti-6Al-4V Parts

In laser powder bed fusion (L-PBF) additive manufacturing, parts are manufactured in a layer-by-layer pattern. In each layer, cross-sections can be scanned with or without partitioning by the laser, which are commonly known as “stripe” and “meander” patterns, respectively. Under the two scanning strategies, the thermal history experienced by the part can be considerably different. Accordingly, defect distribution, microstructure, and mechanical properties may be affected. In this study, two sets of Ti-6Al-4V specimens were fabricated using L-PBF: in one set, the tracks were partitioned in 5-mm stripes, while in the other set, they were partitioned at 100 mm resulting in no stripe seams in the cross-section. It was found that altering the stripe width can considerably affect the laser penetration depth, the defect content, and consequently fatigue performance. However, tensile strength was not much sensitive to changing the stripe width.