Prediction of the Influence of Microstructure On Fatigue Life and Yield Strength in Ti-5Al-5Mo-5V-3Cr-0.5Fe

Beta-solutionized and aged conditions of metastable β-Ti alloys, such as Ti-5Al-5Mo-5V-3Cr-0.5Fe (Timetal 555), can result in a rich variety of microstructures that affect mechanical properties and fractographic features.  In Timetal 555 there is limited data relating the size and distribution of microstructural features to properties such as yield strength and fatigue life. Using neural networks, databases have been developed to quantify the microstructrual dependencies of yield strength in sub-scale tensile tests and fatigue life in four-point bend tests. These interpolative models can be used as predictive tools to investigate microstructrual dependencies using virtual experiments. The fractographic implications of several of these features will also be discussed.