Evaluation of Very High Cycle Fatigue Properties of β-Titanium Alloy by Using an Ultrasonic Tensile-Compressive Fatigue Testing Machine

摘要

β-titanium alloy has been developed recently because β-titanium alloy has better cold workability, proof stress, and tensile strength. In order to use β-titanium alloy for automobile parts subject to cyclic loading, very high cycle fatigue properties of β-titanium alloy should be investigated. In this study, very high cycle fatigue properties of p-titanium alloy Ti-22V-4A1 were evaluated by using an ultrasonic fatigue testing method, which allows us to reduce a fatigue testing period to 1/100 - 1/1000 of that by using conventional testing methods. An S-N diagram and fracture morphology of Ti-22V-4A1 in the very high cycle region were investigated. Fatigue failure was observed and subsurface fracture occurred in the very high cycle region.