A Novel Hybrid Technique for Enhancing Mechanical Properties in Additively Manufactured Steels

This study introduces a novel hybrid manufacturing technique that combines Selective Laser Melting (SLM) with powder metallurgy to enhance the mechanical performance of steel lattice structures. The method involves fabricating shell-lattice components using SLM with 316 L, MS1, and 316 L + 2% Cu powders, followed by targeted sintering and heat treatment to refine the internal porous zones. Three distinct lattice geometries-closed hexagon, re-entrant, and Schwarz-P-were integrated into the design to examine structural behavior under compression. Parts were produced and tested using micro-hardness analysis, scanning electron microscopy, and compression testing. The sintering stage promoted densification and metallurgical bonding within the lattice-filled cavities, resulting in improved mechanical strength and multifunctionality. Results revealed yield strength improvements of up to 250% and toughness increases of 25%, particularly in re-entrant lattices. The technique also enabled the formation of multifunctional zones within a single part, including sintered porous regions, load-bearing lattice walls, and a dense outer shell. These findings demonstrate the potential of the hybrid method to produce lightweight, impact-resistant steel components more efficiently, with strong implications for aerospace, automotive, and defense applications.