Effect of heat treatment on stainless steel 316L alloy sandwich structure fabricated using directed energy deposition and powder bed fusion

Abstract

The present work reports the effect of heat treatment on the mechanical, and microstructural properties of the Stainless Steel 316L (SS316L) alloy sandwich structure manufactured using Directed Energy Deposition (DED) and Powder Bed Fusion (PBF) technique. The SS316L sandwich structure undergoes two heating methods namely, stress relief at 650 °C (HT1) and solution treatment at 1100 °C (HT2). Both heat treatments are maintained for two hours, followed by furnace cooling. The microstructure and mechanical properties of the heat-treated samples and the as-built sample were compared. Heat treatment alters the mechanical and microstructural characteristics of the sandwich structure. Among the heat treatment conditions considered, HT1 obtains a higher micro hardness of 240.2 HV, and HT2 obtains a total elongation of 72.5%.