Effect of duplex aging on microstructure and mechanical behavior of beta titanium alloy Ti–15V–3Cr–3Al–3Sn under unidirectional and cyclic loading conditions. (April 2015)

• Record Type: Journal Article
• Authors: Santhosh, R.; Geetha, M.; Saxena, V.K.; Nageswara Rao, M.
• Is Part Of: International journal of fatigue. Volume 73(2015)
• Page Start: 88
• Page End: 97
• Publication Date: 2015-04
• Subjects: Beta titanium alloy -- Duplex aging -- Microstructure -- Work hardening rate -- HCF behavior; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2014.12.005
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Duplex aging (DA) in place of single aging (SA) of beta titanium alloy 15-3 led to higher strength. Higher strength after DA was related to finer and denser precipitation of α particles. DA resulted in major improvement in HCF life over SA. Freedom from micro-PFZs and grain boundary α led to better HCF life after DA. Improved HCF life after DA was achieved even at a high mean stress level (stress ratio = +0.3). Abstract: 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 α and micro precipitate free zones (micro PFZs) were present in the microstructure. Whereas after DA, grain boundary α 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.