Accession Number : ADA307471

Title :   Corrosion and Corrosion Fatigue of Airframe Materials.

Descriptive Note : Final rept.,

Corporate Author : LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS

Personal Author(s) : Wei, Robert P. ; Harlow, D. G.

PDF Url : ADA307471

Report Date : FEB 1996

Pagination or Media Count : 56

Abstract : In support of the National Aircraft Research Program of the Federal Aviation Administration (FAA) Lehigh University undertook a multidisciplinary program of research to study corrosion and corrosion fatigue of airframe materials. The program is complemented by a program sponsored by the Air Force Office of Scientific Research (AFOSR). The objectives of these programs are (1) the development of basic understanding of the processes of localized corrosion and corrosion fatigue crack nucleation and growth in high-strength aluminum alloys used in airframe construction (2) the formulation of kinetic models for these elemental processes and (3) the integration of these models into probabilistic models that can provide guidance in formulating methodologies for service-life prediction. This report summarizes research performed under the FAA sponsored (Phase I) program for the period from 15 June 1992 to 14 June 1995. Experimental efforts during this period were focused upon (1) characterizations of the chemical microstructural and statistical aspects of pitting corrosion, and upon the kinetics of pitting of 2024-T3 aluminum alloy in aqueous environments; (2) establishment of the criteria for the transition from pitting to corrosion fatigue crack growth (i.e. crack nucleation); and (3) studies of corrosion fatigue crack growth (particularly in its early stage, or the so-called chemically short regime). The modeling effort, which cuts across the FAA and AFOSR programs, included the development and demonstration of a mechanistically based probability approach for service-life prediction and the formulation of a probability model for particle-induced corrosion pit growth that pertains to multiple-site-damage (MSD) analysis.

Descriptors :   *CORROSION, *ALUMINUM ALLOYS, *AIRFRAMES, *FATIGUE(MECHANICS), AIRCRAFT, DAMAGE ASSESSMENT, HIGH STRENGTH ALLOYS, NUCLEATION, CRACK PROPAGATION, PITTING.

Subject Categories : Aircraft
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE