SST Technology Follow-on Program - Phase II. Development and Evaluation of the Aluminum-Brazed Titanium System. Volume VI. Corrosion Resistance.
Abstract
Previous work on the SST prototype and Phase I DOT/SST follow-on programs showed that the environmental corrosion resistance of aluminum-brazed titanium honeycomb sandwich was basically satisfactory. Investigations were conducted in the Phase II follow-on program to explore corrosion resistance of aluminum-brazed titanium over a wider range of environmental conditions and design parameters. The program covered (a) extended flight service tests and engine exhaust exposure tests, (b) accelerated laboratory tests in marine environments, and (c) electrochemical studies of fundamental corrosion mechanisms. Solid-face and perforated-face honeycomb sandwich panel specimens, bolted panel joints, and faying-surface braze joints were investigated. Tests included 4 years' flight service exposure on Model 727 landing gear installations, limited flight service exposure in the NASA YF-12A airplane, 1 year exposure in turbine engine exhaust products, and 1 year exposure in actual and simulated marine environments. Results of Phase II investigations substantiate that titanium brazed with 3003 aluminum alloy is inherently resistant to corrosion under anticipated aircraft service conditions. Corrosion resistance is equivalent to bare 3003 aluminum alloy. Passivation films on both the aluminum and titanium surfaces effectively prevented galvanic coupling under the service environments evaluated. Chromate-inhibited primers provided additional corrosion protection for exposed panel edges. Continued flight service testing IS recommended. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1974
- Accession Number
- AD0920799
Entities
People
- D. T. Lovell
- S. D. Elrod
- W. L. Cotton
- Y. Moji
Organizations
- Boeing