MATERIAL - UNCLAD 2020-T6 ALUMINUM ALLOY. ELEVATED TEMPERATURE - CORROSION PROTECTIVE SURFACE TREATMENTS FOR - DETERMINATION OF
Abstract
Unclad 2020-T6 Al alloy received type I and II anodic coatings (MIL- A-8625A) and Iridite 14-2 coatings (MIL-C-5541). Uncoated and coated panels from each process were subjected to (1) no heat exposure, (2) 100 hr at 300 F, and (3) 100 hr at 350 F. The panels were then exposed to 20% salt spray, 120 F, 95% RH, and 3 phase JP-4 salt water immersion environments. Tensile test results revealed that 100-hr exposure to 300 F had little effect on the tensile properties of coated and uncoated 2020-T6 Al whereas a similar exposure at 350 F decreased the yield and ultimate strengths by 13 to 22%. Specim ns representing all 3 coating processes passed the tensile requirements of MIL-A- 8625A and MIL-C5541 after salt spray exposure alone. However, elevated temperature exposure decreased the salt spray corrosion resistance of all specimens. Type I, Type II and Iridite 14-2 coated 2020-T6 Al alloy exhibited no visible signs of corrosion after 360-hr exposure to 120 F, 95% RH or 48-hr exposure to 3 phase JP-4 salt water immersion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 17, 1962
- Accession Number
- AD0272100
Entities
People
- J. L. Cozart
Organizations
- General Dynamics