Effect of the primary alpha fraction on the dwell fatigue behaviour of Ti-6Al-4V alloy

In this study, the effect of microstructure on dwell-fatigue response for Ti-6Al-4V alloy was studied. Tensile tests and fatigue tests with varying dwell periods and maximum stresses were performed on samples having varying fractions of primary alpha (& alpha;p). Yield and ultimate tensile strength increased with a reduction in the & alpha;p, whereas elongation is highest for the samples with smallest effective grain size. Lowest and highest fatigue/dwell-fatigue lives were obtained for the samples with 74 and 53 % & alpha;p, respectively, with the latter showing lowest dwell debit. Detailed microstructural characterization revealed that alloying element partitioning and colony-sizes were responsible for varying properties.

Automated summary

The study investigated the effect of microstructure on dwell-fatigue response in Ti-6Al-4V alloy. Tensile tests and fatigue tests were conducted on samples with varying fractions of primary alpha phase. Results showed that yield and ultimate tensile strength increased with a decrease in the alpha phase fraction, while the sample with the smallest effective grain size had the highest elongation. Detailed microstructural characterization revealed that alloying element partitioning and colony sizes influenced the properties of the alloy.