Abstract
Additive manufacturing (AM) is a relatively novel technique for various industrial sectors. Due its ability to provide design optimization, efficient material usage, and reduced energy consumption, a wide variety of industries have shown great interest in adopting the different AM techniques. AM has various categories based on the feedstock used in the process. The feedstock can either be wire or powder, in which they are either deposited through a nozzle or scanned in-place. Wire feedstock laser metal deposition (WFLMD) has several advantages over other AM processes. The advantages include lower feedstock costs, high deposition rates, reduced material waste, and the ability to produce large scale parts. However, the capability of achieving a near-net-shape metal is greatly dependent on the optimized processing parameters. In this work, 316L stainless steel (SS) samples produced via WFLMD with different processing parameters and geometries are studied to investigate their microstructural and mechanical properties. The density of the WFLMD samples was measured using the Archimedean principle. Microstructural characterization was performed using optical metallography, scanning electron microscopy, and electron backscatter diffraction. The phase structure of the WFLMD 316L SS samples was characterized by X-ray diffraction. The mechanical properties were examined to determine Vickers microhardness, tensile strength/ductility, creep behavior, and physical property like the thermal expansion coefficient was measured. The microstructural characterization demonstrated variation in microstructural characteristics, mainly, due to the variation of thermal gradients and the scanning vectors length in the samples processing. The microstructural evolution influenced the mechanical properties of the WFLMD samples by enhancing the microhardness, tensile strength, and creep resistance compared to the conventionally processed 316L SS.