Effect of duplex aging on microstructure and mechanical behavior of beta titanium alloy Ti-15V-3Cr-3Al-3Sn under unidirectional and cyclic loading conditions

The microstructure and mechanical behavior of beta titanium alloy Ti-15V-3Cr-3Al-3Sn (Ti15-3) under unidirectional and high cycle fatigue (HCF) loading conditions were studied after single aging (SA) and duplex aging (DA). After SA, well-developed grain boundary at and micro precipitate free zones (micro PFZs) were present in the microstructure. Whereas after DA, grain boundary at was poorly developed and micro PFZs were absent. DA resulted in smaller size, higher density and volume fraction of alpha particles. DA led to higher work hardening rate, better strength-ductility combination and higher HCF life. Improved mechanical behavior after DA is explained based on microstructural observations. (C) 2014 Elsevier Ltd. All rights reserved.