Corrosion-Fatigue Testing of High-Strength Aluminum Alloys Melanie Chatham Advisor: Dr. David Lanning

Problem Overview Corrosion typically combines with other modes of failure Stress-corrosion cracking (SCC) compromises fatigue life –Many high-strength aluminum alloys are susceptible to SCC in saline environments SCC is not well understood

Objectives Understand how SCC affects fatigue life of high-strength aluminums Process: –Build environmental chamber for saline environment –Test under varied fatigue conditions –Analyze S-N data –Observe fracture surfaces

Corrosion Chamber Simulates a wet environment In-situ testing Leak-free during testing Reusable

Testing Saline solution circulated around specimen Environment refreshed from reservoir Salt concentration similar to sea water

Current Progress Leak-free chamber Three preliminary fatigue tests completed –Evaluating low-fatigue life failures –Possible misalignment issue with chamber Observing fracture surfaces of failed specimens

Future Progress Possible chamber improvements Perform fatigue tests under varied conditions –Baseline laboratory air –Saline solution environment –Loading, stress ratio, frequency Inspect fracture surfaces for SCC damage

Questions?