Factors affecting the fatigue strength of additively manufactured Ti-6Al-4V parts

Additively manufactured Ti-6Al-4V parts may show better mechanical properties than those of cast and wrought materials. However there are significant uncertainties on the fatigue properties. In this study, a detailed analysis of Ti-6Al-4V parts was reviewed. A correlation on fatigue properties was observed based on microstructure, surface and internal quality. This relation was formulated in a developed model called MIS (Microstructure, Internal, Surface) that describes the domain of the AM part failing based on surface and internal quality. To assess the fatigue strength, correction factors are determined for two SN-curves within the limits provided.