0
TECHNICAL PAPERS

Fatigue Crack Growth of β-21S Titanium Alloy Under Constant Amplitude and miniTWIST Flight Spectra at 25°C and 175°C

[+] Author and Article Information
R. R. Stephens, T. P. Albertson

Mechanical Engineering, The University of Idaho, Moscow, ID 83843

R. I. Stephens, A. L. Veit

Mechanical Engineering, The University of Iowa, Iowa City, IA 52242

J. Eng. Mater. Technol 119(4), 387-392 (Oct 01, 1997) (6 pages) doi:10.1115/1.2812274 History: Received July 21, 1996; Revised April 16, 1997; Online November 27, 2007

Abstract

β-21S titanium alloy sheet fatigue crack growth behavior was investigated at 25°C and 175°C under constant amplitude (R = 0.1 and 0.5) and miniTWIST flight spectra. Based upon nominal ΔK values, constant amplitude fatigue crack growth behavior at 175°C was either similar to (R = 0.1), or slightly better than (R = 0.5) 25°C. With crack closure taken into account, the fatigue crack growth curves at 175°C, plotted as a function of Keff , were shifted to the left of the fatigue crack growth curves at 25°C at near threshold values. Under flight spectra conditions, fatigue crack growth life at 175°C was 40 to 90 percent longer than at 25°C. Flight spectra life calculations using NASA/FLAGRO based upon constant amplitude fatigue crack growth data, were primarily conservative but in good agreement with experimental data. Fatigue crack growth was transgranular with crystalline facets and striations that were evident at higher constant amplitude fatigue crack growth rates and with the miniTWIST spectra. Striations were observed to a limited extent at threshold and near threshold conditions at 25°C, but not at 175°C. Based upon desirable constant and variable amplitude fatigue crack growth and fatigue/fracture crack morphology, this β-21S sheet alloy appears to be an acceptable material for damage tolerant aerospace situations between 25°C and 175°C.

Copyright © 1997 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In