Kinetics and fracture behavior under cycle loading of an Al–Cu–Mg–Ag alloy

• Published in: Physics of metals and metallography Vol. 117; no. 7; pp. 725 - 734
• Main Authors: Gazizov, M. R., Kaibyshev, R. O.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-07-2016; Springer; Springer Nature B.V
• Subjects: Alloys; Aluminum base alloys; Amplitudes; Chemistry and Materials Science; COPPER ALUMINUM ALLOYS; Cyclic loads; CYCLIC STRESS; DEFORMATION; Elastic deformation; ELASTIC STRAIN; Fatigue (materials); Fatigue strength; KINETICS; Materials Science; MATHEMATICAL ANALYSIS; Metallic Materials; Specialty metals industry; STRAIN; Strain hardening; STRAIN HARDENING MECHANISMS; Strength and Plasticity; fractography; fatigue; Al–Cu–Mg–Ag alloy; microstructure; mechanical properties
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X16050069

The behavior of aluminum alloy AA2139 subjected to T6 treatment, including solution treatment and artificial aging, has been studied using cyclic loading with a constant total strain amplitude. Upon low-cyclic fatigue in the range of total strain amplitudes ε
ac
of 0.4–1.0%, the cyclic behavior of the AA2139-T6 alloy is determined by the processes that occur under the conditions of predominance of the elastic deformation over plastic deformation. The AA2139 alloy exhibits stability to cyclic loading without significant softening. The stress-strained state of the alloy upon cyclic loading can be described by the Hollomon equation with the cyclic strength coefficient
K
' and the cyclic strain-hardening exponent
n
' equal to 641 MPa and 0.066, respectively. The dependence of the number of cycles to fracture on the loading amplitude and its components (amplitudes of the plastic and elastic deformation) is described by a Basquin–Manson–Coffin equation with the parameters σ′/
E
= 0.014,
b
=–0.123, ε′
f
= 178.65, and
c
=–1.677.