The effect of cubic-texture on fatigue cracking in a metastable β titanium alloy subjected to high-cycle fatigue

摘要

In this work, stress-controlled high-cycle fatigue tests were performed on Ti-7Mo-3Nb-3Cr-3Al alloy with β-cubic texture to investigate fatigue crack-initiation mechanisms and microstructurally small fatigue crack growth behaviors. The S-N curve shows a general feature of monotonic increase in the mean lifetime with decreasing stress level. Fatigue crack-initiation sites revealed the contiguous β facets. The fracture surface observations and the slip trace analysis show that most faceting occurred in {110} <111> slip system with the highest Schmid factor. Besides, a higher Kernel average misorientation (KAM) was found in fatigued microstructure. This strain localization would contribute to the fatigue crack-initiation process.