Investigating the Mechanical Behavior of 5XXX Aluminum Alloy Structures on HMCS Iroquois
Abstract
ABSTRACT The proposed work will conduct a thorough investigation of the microstructure-property relationships in 5XXX Aluminum Alloy(s) removed from the HMCS Iroquois that is currently docked at CFB Halifax. The HMCS Iroquois (DDG 280) is an Iroquois-class destroyer that served the Canadian Forces from 1972 until 2014. This 42-year service history provides a unique opportunity to critically evaluate the effects of service-related exposures to environment/thermal excursions on the current microstructure and current mechanical properties of pedigree material. Ongoing work on other ONR-sponsored programs is evaluating the effects of various time/temperature exposures on microstructure/property relationships by starting with pristine (i.e. as-received) pedigree material, while the proposed work provides a unique opportunity to connect these studies with similar material(s) that have experienced significant service. The proposed work intends to determine the effects of a 42-year service history on resulting microstructure and mechanical properties of 5XXX Aluminum Alloys present on the HMCS Iroqouis using a combination of advanced micro/nano-structure and mechanical characterization techniques. Most current efforts to understand the effects of sensitization on 5xxx series Al alloy mechanical properties and stress corrosion cracking issues have focused on the study of beta-equilibrium precipitates on pedigree samples that have received accelerated exposure treatments at high temperatures (e.g. 175¡C) for relatively short (e.g. 100 hours) times. While complimentary work by the Lewandowski group at CWRU is examining thermally exposed 5083 and 5456 at temperatures ranging from 60¡C to 175¡C for times ranging from 1 hour to 20,000 hours, there is an urgent need to examine materials with sufficient service history to provide a quantitative comparison. This proposal presents our approach at CWRU to systematically evaluate the effects of a 42-year service history on the micro/nano-structure and relevant mechanical properties of 5XXX series Aluminum alloys excised from the HMCS Iroquois. This CWRU work will provide a more complete characterization of relevant materials and actual service exposures while also enabling comparison to other ongoing work focusing on laboratory studies of time/temperature exposures.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 22, 2016
- Source ID
- N000141512445
Entities
People
- John J. Lewandowski
Organizations
- Case Western Reserve University
- Office of Naval Research
- United States Navy