Additive and Subtractive Hybrid Manufacturing (ASHM) of 316L Stainless Steel: Single-Track Specimens, Microstructure, and Mechanical Properties

Abstract

The present work investigates the influence of the laser power (P) and scanning speed (v) on the surface morphology and Vickers microhardness of single scan tracks formed by directed energy deposition (DED) to determine suitable parameter values for further in-depth investigation of additive and subtractive hybrid manufacturing (ASHM) of fabricated parts. The experimental results show that the depth and width of the melt pool depended significantly on both P and v. Furthermore, the anisotropic mechanical behavior of bulk 316L specimens fabricated by ASHM in the horizontal (H), edge (E), and vertical (V) directions relating to the build layers was also explored. The results show that the tensile strength of the specimens fabricated by ASHM in the H direction was higher than that of those built in the E or V direction, implying that the anisotropy originates from the unique thermal history of each component location owing to the layer-by-layer nature of the DED process.