Reducing anisotropic material properties of additively manufactured Ti-6Al-4V parts via interval island laser scanning method

Abstract

The Powder Bed Fusion (PBF) process using Ti-6Al-4V powder has special applications in the manufacture of high-value mechanical parts in the aerospace and medical industries. PBF is the accumulation of laser-assisted melting layers. High thermal stresses, residual stresses, and local temperature variations occur during rapid melting and cooling in processes that affect the anisotropic mechanical properties of additive manufacturing components. In this work, we analyzed the effective scanning strategy of additive manufacturing and its effect on the mechanical properties, microstructure, and residual stresses of the part. Three commonly used scanning methods to reduce the anisotropic material properties resulting from the PBF process of Ti-6Al-4V: strip, continuous island, and interval island scanning strategies are explicitly analyzed and compared. Through the cantilever experiment, it was confirmed that the interval island scan method reduces deformation by up to 12.6% compared to the conventional strip scan method due to the reduction of anisotropic residual stress.