|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||Optimization of Stress Corrosion Mitigation in Al-Mg via Zn-Rich Primers
||Matthew McMahon, Eric Dau, Allison Akman
|On-Site Speaker (Planned)
The Al-Mg alloy AA5456 achieves a unique combination of weldability, general marine corrosion resistance, and high strength-to-weight ratio when utilized at relatively low temperatures in service. However, prolonged exposure to temperatures of at least 40ᵒC promotes Mg diffusion to the grain boundaries to form the highly anodic β phase in a process termed sensitization, which promotes stress corrosion cracking (SCC) and premature failure in seawater conditions. When these conditions cannot be avoided, a versatile cathodic protection system is useful to reduce or eliminate the rapid β dissolution and potential for SCC. Previous work demonstrated that inorganic Zn-rich primers have a unique capability to fill this role. This work will evaluate the efficacy of these primers in full immersion conditions in order to understand if specific inorganic Zn-rich primer attributes exist that enable their uniquely high level of cathodic protection performance and SCC mitigation on highly sensitized AA5456.
||Aluminum, Other, Other