Effect of aging on the fatigue crack growth kinetics of an Al-Zn-Mg-Cu alloy in two directions

Journal Article · Tue Feb 15 04:00:00 EST 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90597-5· OSTI ID:5386031

Alpay, S P; Guerbuez, R ^[1]

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1. Middle East Technical Univ., Ankara (Turkey). Dept. of Metallurgical Engineering

There have been investigations discussing the effect of aging condition, and thereby the microstructure, on the fatigue crack growth characteristics of precipitation hardening alloys. Lindigkeit et al.., testing an Al-Zn-Mg-Cu alloy of composition corresponding to the commercial alloy 7075 concluded that the crack propagation resistance of underaged microstructures with shearable precipitates is significantly higher than overaged samples of same strength containing non-shearable particles. They reported that this behavior cannot be explained on the basis of slip reversibility alone. A similar conclusion is drawn by Zaiken and Ritchie from investigations on the effect of microstructure on the fatigue crack growth rate of an 7150 aluminum alloy, which is a somewhat high-purity version of the alloy 7050, with lower Fe and Si contents. It is also interesting that aging conditions showing high resistance to fatigue crack growth at low [Delta]K regimes, do not necessarily retain their superiority at medium and high stress intensity ranges.

• OSTI ID: 5386031
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 30:4; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
COPPER ALLOYS
CRACK PROPAGATION
MAGNESIUM ALLOYS
MICROSTRUCTURE
ZINC ALLOYS