A Study of the effect of grain boundary character in Recrystallized and UnRecrystallized Aluminum alloys

Abstract

The 5xxx series Al alloys based on the Al-Mg systems, are widely used in transportation, pressure vessels, marine, and other applications due to their high strength, good weldability and favorable corrosion resistance. In contrast to heat treatable alloys such as the 2xxx, 6xxx, and 7xxx series, in which a desired level of mechanical strength is achieved by thermal heattreatments for precipitation hardening purposes, strength in 5xxx alloys Al-Mg alloys is achieved primarily by solid solution strengthening, dispersion hardening, and/or work hardening. However, intergranular corrosion and intergranular stress corrosion cracking becomes a concern for alloys containing 4.0-5.5wt% Mg (such as AA5356, AA5083 and AA5456) when subjected to sustained temperatures above 50oC. This intergranular corrosion issue is caused by the precipitation of Al3Mg2 (?? phase) at the grain boundaries, where this precipitation is termed as ???sensitization??? of Al-Mg alloys. Therefore, the research objective of this proposal is to explore the presence and formation of ??, ????? and ????? precipitation in recrystallized and unrecrystallized Al/Mg alloys, specifically, the role of composition and grain boundary character in improving the sensitization and corrosion behavior. The aim is to design and synthesize new engineering high performance long lasting materials that will reduce the cost of ownership of essential equipment needed for DoN missions.

Document Details

Document Type
DoD Grant Award
Publication Date
Jul 26, 2018
Source ID
N000141812617

Entities

People

  • Andrea Hodge

Organizations

  • Office of Naval Research
  • United States Navy
  • University of Southern California

Tags

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.