Additive Manufacturing of 316L Steel: Investigation of Thermal Stability and Crystalline Properties

Additive Manufacturing (AM) technology is a growing industry in the world of engineering. Similar to 3D printing, AM technology allows designers to create metal parts without the limitation of geometric restrictions of traditional methods, like machining. AM can be applied in industries such as biomedical and aerospace. The AM research conducted at West Texas A&M University (WTAMU) uses laser technology for powder-bed infusion (PBLF) using an SLM 125 to print 316L stainless steel parts. Although AM offers a wide variety of application, AM technology cannot produce consistent parts due to unknown factors that create defects in the part and impact the resultant material properties. In this study, a thermal analysis was conducted on printed 316 L Stainless Steel samples using a Differential Scanning Calorimeter (DSC) and Thermogravimetric Analysis (TGA) to record phase change, melting points, other transitions like oxidation and decomposition and mass loss/gain. Thermal analysis demonstrated a comparative thermal stability of the printed steel. Additionally, the samples were analyzed with an X-Ray Powder Diffraction (XRD) machine for crystallinity of printed steel and a baseline elemental analysis. Results of the XRD analysis indicate the printed material is not entirely crystalline in structure and further analysis is needed to develop a standard XRD profile for AM 316L Stainless Steel. The findings of this study indicate the PBLF process changes the thermal properties of power material and the need for future studies to understand the impacts of material properties.