Metallurgical Studies on Cracked Al–5.5Zn–2.5Mg–1.5Cu Aluminum Alloy Injector Disc of Turbine Rotor
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The high-strength aluminum alloy Al–5.5Zn–2.5Mg–1.5Cu (AA 7075) is extensively used in aerospace applications. An injector body of a gas generator for a turbine rotor in a liquid propulsion system was fabricated out of AA 7075 forgings in the T7352 condition, and, subsequent to a qualification hot test, one of the injector discs showed the presence of cracks on the top face of the body. Detailed metallurgical investigation indicated that the failure was caused by stress-corrosion cracking (SCC).
KeywordsStress-corrosion cracking AA 7075 aluminum alloy
The authors express their sincere thanks to Shri M.C. Mittal, Group Director, Materials and Metallurgy Group, VSSC, and Dr. K.N. Ninan, Deputy Director, VSSC, for their guidance and encouragement during the work. They are indebted to Dr. B.N. Suresh, Director, VSSC, Trivandrum for his permission to publish this work.
- 1.Aerospace Material Specification, AMS 4311B, issue 7-1-76, revision 10-1-88, SAE The Engineering Society for Advancing Mobility Land Sea Air and Space, Warrendale, PAGoogle Scholar
- 2.Fractography and Atlas of Fractographs, vol. 9, 8th edn., American Society for Metals, Metals Park, OH, p. 78 (1974)Google Scholar
- 4.Talianker, M., Cina, B.: Metall. Trans. A, 20A, 2087, (1989)Google Scholar
- 5.Lumley, R.N., Polmear, I.J., Morton, A.J.: Novel ageing treatments to enhance mechanical properties of aluminium alloy, Proceedings from Materials Solutions Conference, 5–8 Nov 2001 (Indianapolis, IN), ASM International, p. 248 (2001)Google Scholar
- 6.Puiggadi, M., Zielinski, A., Olive, J.M., Renauld, E., Desjardins, D., Cid, M.: Corros. Sci. 40(4/5), 804 (1998)Google Scholar
- 7.Corrosion, vol. 13, 9th edn., Metals Handbook, American Society for Metals, Metals Park, OH, p. 593 (1987)Google Scholar
- 8.Light Alloys: Metallurgy of the Light Metals, 3rd edn., I.J. Polmear, Arnold, London, p. 62 (1995)Google Scholar
- 9.Failure Analysis and Prevention, vol. 10, 8th edn., Metals Handbook, American Society for Metals, Metals Park, OH, p. 205 (1975)Google Scholar