Factors Affecting the Early Stages of Corrosion-Fatigue in Commercial Aircraft Skin
Corrosion-fatigue tests were performed on tapered laboratory specimens of skin material obtained from a retired commercial aircraft. The early stages of corrosion-fatigue damage were examined in the as-received condition (with paint and clad intact), in the absence of paint, and without paint or cladding. Cracks were found to nucleate preferentially in the clad layer near prismatic pit colonies. The crack nucleation rate was affected by pH and the exposed clad/core area ratio. The growth rate of small cracks was not influenced by pH or exposed clad/core area ratio.
KeywordsFatigue Crack Crack Growth Rate Corrosion Fatigue Crevice Corrosion Clothe Layer
Unable to display preview. Download preview PDF.
- J. C. Newman, Jr., and I. S. Raju, “Stress Intensity Factor Equations for Cracks in Three-Dimensional Finite Bodies,” NASA Tech. Memo. 83200 (1981), pp. 1 – 49, as quoted in Stress Intensity Factors Handbook, Vol. 2, Y. Murakami, Ed., Pergamon, New York (1990).Google Scholar
- H. Kaesche, “Pitting Corrosion of Aluminum and Intergranular Corrosion of Aluminum Alloys,” in Localized Corrosion, NACE-3, R. W. Staehle, B. F. Brown, J. Kruger, and A. Agarwal, Eds., National Association of Corrosion Engineers, Houston, TX (1974), pp. 516–525.Google Scholar
- G. S. Chen, M. Gao, D. G. Harlow, and R. P. Wei, “Corrosion and Corrosion Fatigue of Airframe Aluminum Alloys,” FAA/NASA International Symposium of Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, C. E. Harris, Ed., NASA Conference Publication 3274, Langley Research Center, Hampton, VA (1994), pp. 157–173.Google Scholar
- M. Pourbaix, “Atlas of Electrochemical Equilibria in Aqueous Solutions,” National Association of Corrosion Engineers, Houston, TX (1974), pp. 168–176.Google Scholar
- R. S. Piascik and S. A. Willard, “The Growth of Small Corrosion Fatigue Cracks in Alloy 2024,” NASA Tech. Memo. 107755 (1993).Google Scholar
- N.J.H. Holroyd, “Environment-Induced Cracking of High-Strength Aluminum Alloys,” in Environmentally Induced Cracking of Metals, NACE-10, R. P. Gangloff and M. B. Ives, Eds., National Association of Corrosion Engineers, Houston, TX (1990), pp. 311–345.Google Scholar