Rapidly solidified microstructure of 3D parts fabricated by selective laser melting (SLM) - Examples of stainless steel 316L and titanium Ti-6Al-4V

Laser additive manufacturing process capable of producing fully dense metallic parts direct from 3D CAD know a fast development. Major concerns are made to achieve the best accuracy of the final geometry and the reduction of the residual stresses but metallurgical aspects are also essential. The process can be described as a succession of very small welds. A key in the optimization of the mechanical properties is the understanding of the specific solidification mechanisms. Microstructures of two alloys were studied by metallographic examination and EBSD analysis.