Effect of laser energy density on microstructures and mechanical properties of selective laser melted Ti-6Al-4V alloy

Ti-6Al-4V samples were fabricated by selective laser melting (SLM) with a series of different laser energy inputs. The microstructure presented a feature of fine acicular martensite due to the high cooling rate of the SLM process. All the relative density, micro-hardness and tensile properties initially increased and then decreased with increasing laser energy density. The fracture morphology exhibited a mixed mode of complex ductile and brittle fracture. All the results indicated that the laser energy density has a crucial effect on the microstructures and mechanical properties of the SLMed Ti-6Al-4V alloy. The correlations between the laser energy density and the microstructures and mechanical properties of the SLMed Ti-6Al-4V alloy were studied.