The effect of SLM process parameters on density, hardness, tensile strength and surface quality of Ti-6Al-4V

In this paper, we printed Ti-6Al-4V SLM parts based on Taguchi design of experiment and related standards to measure and compare hardness with different mechanical properties that were obtained in our previous research such as density, strength, elongation, and average surface. Then the effect of process parameters comprising laser power, scan speed, hatch space, laser pattern angle coupling, along with heat treatment as a post-process, in relation to hardness was analysed. The relation of measured factors with each other was also studied and related mechanisms were discussed in depth. The original contribution in this paper is in producing a large and precise dataset and the comparison with mechanical properties. Another contribution is related to the analysis of process parameters in relation to hardness and explaining them by rheological phenomena. The results showed an interesting similarity between hardness and density which is highly related to the formation of the melting pool and porosities within the process.