Title

Mitigating Intergranular Stress Corrosion Cracking in Age-Hardenable Al-Zn-Mg-Cu Alloys.

Authors

Ajay Krishnan, M.; Raja, V. S.; Shukla, Shweta; Vaidya, S. M.

Abstract

This article reports an attempt to develop high-strength aluminum alloys of 7xxx series resistant to intergranular stress corrosion cracking (SCC). A novel aging technique reported in this work exhibited improved strength levels (as high as ~ 100 MPa to that of conventional overaged temper for AA 7050) with significant resistance to SCC measured even at a low strain rate (10−7 s−1) in 3.5 wt pct NaCl. The novel aging heat treatment produced a microstructure that is finer and dense enough in the matrix to impart strength, whereas it is enriched with Cu on the grain boundaries to impart SCC resistance. A detailed explanation for the enhanced strength and SCC resistance is discussed.

Subjects

CORROSION & anti-corrosives; ALUMINUM alloys; STRESS corrosion cracking; STRAINS & stresses (Mechanics); HEAT treatment; MICROSTRUCTURE

Publication

Metallurgical & Materials Transactions. Part A, 2018, Vol 49, Issue 6, p2487

ISSN

1073-5623

Publication type

Academic Journal

DOI

10.1007/s11661-018-4601-8