(V) Corrosion performance of additively manufactured stainless steel produced by modified feedstock

Selective laser melting (SLM) is a popular additive manufacturing (AM) technique used for fabrication of complex 3D components via layer-by-layer. The components produced by SLM are often reported to have porosity which influences the corrosion and mechanical performance of the component. Optimization of SLM processing parameters and post-processing are conducted increase densification, minimize porosity and meet the requirement of high corrosion resistance. Post-processing increases the cost of the components. Therefore, using a modified feedstock powder would help in eliminating the expensive step of post-processing. Modified feedstock powders are produced via high energy ball milling of certain selected additives and 316L stainless steel powders. The additives were selected prioritizing the improvement in corrosion performance. The coupons produced with the modified feedstock powders had accomplished significant improvement in corrosion behaviour as investigated by comparing the pitting potential and repassivation potentials. The microstructure was investigated using scanning electron microscope and transmission electron microscope coupled with energy-dispersive X-ray spectroscopy.