Effect of Post-Processing and Porosity on Fatigue Performance of Selective Laser Melted Ti-6Al-4V ELI

摘要

Conclusions: Rotopolishing and SILC cleaning improved the failure strain of solid and surface porous samples due to the decreased roughness. As expected, porous samples had lower properties compared to solid and surface porous samples, regardless of post-processing treatment. Fatigue strength was dependent upon surface roughness, where the smoothest surface had the highest fatigue strength. As surface roughness increased, the fatigue strength decreased due to increased number of sites for crack initiation. Once the porous structure is the dominant structural feature, the impact of post-processing treatment on fatigue is minimal. For SLM devices under high loading conditions, surface porosity can be added without a large decrease in monotonic properties, but fatigue strength will decrease due to the porosity even with a post-processing treatment. The impact of surface porosity is similar to that of a rough finish on an "as-built" sample.