Self-organization of Cu–Ag during controlled severe plastic deformation at high temperatures. Issue 12 (8th June 2015)

• Record Type: Journal Article
• Authors: Arshad, Salman N.; Lach, Timothy G.; Ivanisenko, Julia; Setman, Daria; Bellon, Pascal; Dillon, Shen J.; Averback, Robert S.
• Is Part Of: Journal of materials research. Volume 30:Issue 12(2015)
• Page Start: 1943
• Page End: 1956
• Publication Date: 2015-06-08
• Subjects: mechanical alloying, -- Cu, -- Ag; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1557/jmr.2015.119
• Languages: English
• ISSNs: 0884-2914

Abstract

Abstract: Abstract : Cu90 Ag10 alloys were subjected to severe plastic deformation at temperatures ranging from 25 to 400 °C and strain rates ranging from 0.1 to 6.25 s −1 using high-pressure torsion. The deformed samples were characterized by x-ray diffraction, transmission electron microscopy, and atom-probe tomography. A dynamic competition between shear-induced mixing and thermally activated decomposition led to the self-organization of the Cu–Ag system at length scales varying from a few atomic distances at room temperature to ≈50 nm at 400 °C. Steady-state microstructural length scales were minimally affected by varying the strain rate, although at 400 °C, the grain morphology did depend on strain-rate. Our results show that diffusion below 300 °C is dominated by nonequilibrium vacancies, and by comparison with previous Kinetic Monte Carlo simulations [D. Schwen et al., J. Mater. Res. 28, 2687–2693 (2013)], their concentration could be obtained.