Mechanical and Plastic Properties of Elements Made of Steel X5CrNiCuNb16-4 Using the Selective Laser Melting Technique (SLM)

The article presents results of tests performed using an MCP HEK Realizer II system applied in the selective laser melting (SLM) of metallic powders. Specimens subjected to the SLM process were made of powder, the chemical composition of which corresponded to that of solid steel X5CrNiCuNb16-4. The material was subjected to mechanical tests (concerning tensile and impact strength) and compared with the properties of the solid steel. The research-related tests also involved microstructural observations involving the use of a Neophot 32 metallographic microscope (Zeiss) and fractographic analysis. The tests revealed that the mechanical properties of the printed material subjected to the SLM process were lower (R_0.2 by 45% and R_m by 35%) than those of the solid material and were determined by the properties of the metallic matrix and the porosity of the printed element, the average value of which amounted to 3%. The mechanical properties of the printed material were also significantly affected by the direction of the external load in relation to the orientation of the deposited layers of the material (which was demonstrated during impact bend tests). The summary contains the assessment of the tests and the presentation of advantages resulting from the application of the new technology enabling the volumetric consolidation of metallic powder.