Crack Growth Behavior in ATI 718Plus^® Alloy

Abstract:

ATI 718Plus^® alloy is a new, cast and wrought, Ni-base superalloy with a maximum use temperature approximately 55°C higher than alloy 718. The mechanical properties have been well characterized by turbine engine OEM’s and the alloy has been specified for use as static components and blades in gas turbine engines. Broader use of ATI 718Plus alloy in engine disk applications requires detailed understanding of the damage tolerance under creep and cyclic loading conditions. The results of a large testing program to evaluate the crack growth behavior of ATI 718Plus alloy at temperatures between 649°C and 704°C under conditions of fatigue, dwell-fatigue, and creep are presented. Crack growth rates in ATI 718Plus alloy in this temperature range are lower than alloy 718 and comparable to Waspaloy under non-dwell-fatigue conditions, and comparable to alloy 720 in dwell-fatigue tests.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 2428-2433
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.2428
• Online since: January 2012
• Authors: E. T. McDevitt, S. M. Oppenheimer, R. M. Kearsey, J. Tsang
• Keywords: ATI 718Plus, Creep Crack Growth, Fatigue Crack Growth (FCG), Ni-Base Alloys, Turbine Disks

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