Geometrical Scale-Sensitive Fatigue Properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloys With α/β Lamellar Microstructures

摘要

Fatigue properties of the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy sheets containing different numbers of α/β Widmansttten colonies in the thickness direction of the sheets were investigated by tensionetension fatigue testing. It is found that fatigue properties of the Ti alloy either in low- or high-stress amplitude regimes become more sensitive to the sheet thickness of the Ti alloy as the sheet thickness is comparable to the length scale of the Widmansttten colonies. The basic mechanism of such length scale-sensitive fatigue properties in the Ti alloy was elucidated.