MACHINING BEHAVIOR AND MATERIAL PROPERTIES IN ADDITIVE MANUFACTURING TI-6AL-4V PARTS

Although Additive Manufacturing (AM) has unique advantages in processing complex part designs using superalloys, metal AM parts currently do not meet the part tolerance and surface finish requirements for most mechanical applications. Hence, there is a growing need for integrated metal hybrid manufacturing through both "in-envelope" and "sequential" additive-subtractive manufacturing. Since AM parts are inherently different from traditionally manufactured parts (e.g., anisotropy, residual stress), there is a critical gap in the literature to correlate as-built AM material properties, material characterization, machining parameters with resulting machining behavior such as cutting force and specific cutting energy. This study reports on the machining behavior of Electron Beam Melting (EBM) and Laser Powder Bed Fusion (L-PBF) processed Ti-6Al-4V parts with highly textured microstructure due to build orientation, and heat treatment across different machining conditions. It was found that specific cutting energy of AM parts changes up to 21.6% based on AM processing, cessed parts, build orientation, and heat treatment conditions. The finding from this study can be used to predict machining behavior based on material characterization. In the future, this study will lead to creating a correlation model on AM parts microstructure and correlated machining behavior, surface finish, and tool wear behavior.