Enhanced fatigue properties of ultrafine-grained Ti rods processed by ECAP-Conform

This study is focused on enhancement of the fatigue properties of Ultrafine Grain titanium (UFG Ti) processed by ECAP-Conform and subsequent drawing. By examining specific combinations of ECAP-Conform and drawing, we have shown that the size and shape of grains, dislocation substructure formation, and grain boundary state are among the main microstructural parameters that determine the strength and ductility in UFG Ti. The increase in fatigue resistance of UFG Ti to 610 MPa was attributed to the high values of strength and ductility (UTS = 1290 MPa with elongation = 13 %) This value is comparable with the fatigue resistance of the titanium alloy Ti-6Al-4V.