Correlation of Microstructural Evolution with Mechanical and Tribological Behaviour of SS 304 Specimens Developed Through SLM Technique

Abstract: This research work focuses on the development of SS 304 specimens using the selective laser melting technique and analyses the microstructural modifications. Further, it correlates the evolution of microstructure with mechanical properties like microhardness, nanoindentation and tribological behaviour. The conventionally prepared as-cast SS 304 specimens were taken for comparison of the results obtained with the SLM technique. The diffraction pattern obtained from x-rays disclosed the absence of δ phase and confirmed that refinement of grains occurred in the structural level through decrease in the intensity of α peaks. Optical micrograph witnessed that the grains were in micron and sub-micron size. SEM images depicted the presence of columnar and cellular sub-grains within a grain which were in ultrafine level. The microhardness and nanoindentation results obtained for the SLM specimen were almost multiple times higher than the conventional as-cast specimens. There was a significant improvement in the wear resistance in the SLM specimens than the conventional as-cast specimens. From the results, SLM is found to be a favourable technique to manufacture metallic components in a way to obtain a good service life of engineering components. Graphic Abstract: [Figure not available: see fulltext.]