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Stress ratio, elevated temperature and microstructural effects on the near-threshold fatigue behavior of titanium alloys

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Date Issued:
1993
Summary:
The effect of stress ratio, elevated temperature and differences in microstructure on the near-threshold fatigue crack growth behavior of Titanium alloys was investigated. Near-threshold fatigue testing was conducted on Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-2Sn-4Zr-6Mo at stress ratios of 0.1 and 0.5 and at temperatures of 400 ℉ and 800 ℉. It was found that an increase in stress ratio resulted in an increase in growth rates and a decrease in the fatigue threshold. Increasing the temperature also resulted in faster growth rates and a lower threshold. There was slight differences in growth rates between the two alloys due to microstructural differences. Crack closure could effectively remove some of the effects of stress ratio and microstructural differences but could not remove the effect of the higher temperature. Fractographs revealed the difference in microstructure but did not show significant changes in fracture modes between temperatures.
Title: Stress ratio, elevated temperature and microstructural effects on the near-threshold fatigue behavior of titanium alloys.
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Name(s): Hunter, Kelvin Lee.
Florida Atlantic University, Degree grantor
Salivar, Gary C., Thesis advisor
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Issuance: monographic
Date Issued: 1993
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 132 p.
Language(s): English
Summary: The effect of stress ratio, elevated temperature and differences in microstructure on the near-threshold fatigue crack growth behavior of Titanium alloys was investigated. Near-threshold fatigue testing was conducted on Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-2Sn-4Zr-6Mo at stress ratios of 0.1 and 0.5 and at temperatures of 400 ℉ and 800 ℉. It was found that an increase in stress ratio resulted in an increase in growth rates and a decrease in the fatigue threshold. Increasing the temperature also resulted in faster growth rates and a lower threshold. There was slight differences in growth rates between the two alloys due to microstructural differences. Crack closure could effectively remove some of the effects of stress ratio and microstructural differences but could not remove the effect of the higher temperature. Fractographs revealed the difference in microstructure but did not show significant changes in fracture modes between temperatures.
Identifier: 14884 (digitool), FADT14884 (IID), fau:11669 (fedora)
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): College of Engineering and Computer Science
Thesis (M.S.E.)--Florida Atlantic University, 1993.
Subject(s): Titanium alloys--Fatigue--Testing
Materials--Fatigue--Testing
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fcla/dt/14884
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.