Material Performance of Naturally Sensitized Aluminum 5xxx Alloys

Current understanding of the effect of sensitization on 5xxx aluminum mechanical property performance is limited. Sensitization of aluminum in-service has lead to severe cracking in marine structures. Degree of sensitization measurements taken near cracks in naturally-sensitized aluminum plates have shown high (>40 mg/cm(2)) levels of sensitization. This effort will examine the degree of sensitization, microstructure, tensile, and fracture toughness of several specimens of naturally sensitized aluminum in an attempt to correlate degree of sensitization with material performance. The resulting data can be used to understand how degree of sensitization degrades performance of aluminum ship structures and can influence maintenance or repair decisions. This study is unique, in that it examines the performance of naturally-sensitized aluminum in lieu of artificially (laboratory) sensitized materials.