Minimizing corrosion in 4.0-5.5wt% Mg content Al alloys: the role of composition and grain boundary character
Abstract
PI: Andrea M. Hodge Institution: University of Southern California Project Title: Minimizing corrosion in 4.0-5.5wt % Mg content Al alloys: the role of composition and grain boundary character in ?, ?’, and ?” precipitation Total Funds requested: $276, 917 For naval applications, the term “sensitization” typically refers to the precipitation of Mg2Al3 (? phase) at grain boundaries in Al-Mg alloys. In general, sensitization can lead to intergranular corrosion and intergranular stress corrosion when Al-Mg alloys are sustained temperatures above 50oC. However, additional types of precipitates such as ?’ and ?” have also been reported to occur during sensitization; although the extent of the ?’ and ?” sensitization and their impact on Al-Mg alloys is still unexplored. Therefore, the research objective of this proposal is to explore the presence and formation of ?, ?’ and ?” precipitation in Al-Mg alloys with 4.0-5.5wt % Mg content which include highly relevant alloys such as Al5356, Al5083 and Al5456. Specifically, the role of composition and grain boundary character in improving the sensitization and corrosion behavior will be studied. By implementing a combinatorial approach of corrosion science, materials processing and extensive characterization, this project aims to enhance our general knowledge about ?, ?’ and ?” precipitation under corrosive exposures (direct and indirect). The processing approach will consist of fabricating Al-Mg alloys films with specific grain boundary networks, and subject them to different sensitization conditions. The study will first focus on two scientifically relevant metals for sea corrosion studies: Al5083 and Al5456. Overall, this project will present highly engineered microstructures that can be tailored to last longer under direct and indirect corrosive environments and thus reduce the cost of ownership of essential equipment needed for DoD missions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512486
Entities
People
- Andrea M. Hodge
Organizations
- Office of Naval Research
- United States Navy
- University of Southern California