Studying the influence of initial powder characteristics on the properties of final parts manufactured by the selective laser melting technology

Selective laser melting (SLM) is an additive manufacturing process that enables direct manufacturing of 3D complex shape parts and internal architecture from powder materials. The SLM technology is characterised by high temperature gradients and solidification rates that have a significant effect on the microstructures and properties of final parts. The present paper aims at understanding the influence of the initial properties of various martensitic stainless steel powders on the final microstructures and mechanical properties of parts manufactured using the same optimised SLM process parameter settings. The results obtained show that for applied optimum process parameters, the thermal effects are the same for all martensitic powders used. Besides, the final microstructures and properties are different. The results clearly show the effect of the initial complex chemical composition of the martensitic precipitation hardening powder on the microstructures of final parts, and consequently, on their properties.