Thermal stability of Cu-Cr-Zr alloy processed by equal-channel angular pressing

Journal Article · Mon Aug 15 04:00:00 EDT 2016 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.07.006· OSTI ID:22689600

Abib, Khadidja ^[1]; Azzeddine, Hiba ^[1]; Tirsatine, Kamel ^[1]; Baudin, Thierry; Helbert, Anne-Laure; Brisset, François ^[2]; Alili, Baya; Bradai, Djamel ^[1]

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1. Faculty of Physics, University of Sciences and Technology Houari Boumediène, BP 32 El-Alia, Algiers (Algeria)
2. ICMMO, Univ Paris-Sud, Université Paris-Saclay, UMR CNRS 8182, 91405 Orsay Cedex (France)

Thermal stability of a Cu-Cr-Zr alloy processed by equal-channel angular pressing up to16 passes was investigated using isochronal annealing ranging from 250 to 850 °C for 1 h. The microstructure, crystallographic texture and micro hardness of samples were characterized through electron back scatter diffraction and Vickers micro hardness measurements. The recrystallized grain size was stable between 250 °C and 500 °C then increased quickly. The achieved mean grain size, after 1, 4 and 16 ECAP passes, was around 5.5 μm. A discontinuous mode of recrystallization was found to occur and a Particle Simulated Nucleation mechanism was evidenced. The evolution of the high angle grain boundary fraction increased notably after annealing above 550 °C. The crystallographic texture after isochronal annealing was similar to that of ECAP simple shear, no change of the texture during annealing was observed but only slight intensity variations. Micro hardness of all Cu–Cr–Zr samples showed a hardening with two peaks at 400 and 500 °C associated with precipitation of Cu cluster and Cu{sub 5}Zr phase respectively, followed by a subsequent softening upon increasing the annealing temperature due to recrystallization. - Highlight: •The Cu-1Cr-0.1Zr alloy shows a very good thermal stability up to 550 °C after ECAP. •A discontinuous recrystallization was found to occur and PSN mechanism was evidenced. •The annealing texture was found weak and some new components appear. •Hardening is attributed to the Cr clustering followed by the Cu{sub 51}Zr{sub 14} precipitation. •Softening is a result of recrystallization and grain growth progressing.

• OSTI ID: 22689600
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 118; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BACKSCATTERING
CHROMIUM ALLOYS
COPPER ALLOYS
CRYSTALLOGRAPHY
ELECTRON DIFFRACTION
GRAIN BOUNDARIES
GRAIN GROWTH
GRAIN SIZE
HARDENING
HARDNESS
PEAKS
PRECIPITATION
PRESSING
RECRYSTALLIZATION
SHEAR
STABILITY
TEXTURE
ZIRCONIUM ALLOYS