Giant Young’S Modulus Variations in Ultrafine-Grained Copper Caused by Texture Changes at Post-Spd Heat Treatment / Gigantyczne Zmiany Modułu Younga W Ultra Drobnoziarnistej Miedzi Spowodowane Przez Zmiany Tekstury W Trakcie Obróbki Cieplnej Po SPD
The effect of annealing on dynamic Young’s modulus, E, of ultrafine-grained (UFG) copper obtained by combined severe plastic deformation (SPD) is investigated. It is established that Young’s modulus in the SPD-prepared samples exceeds that in the coarse-grained fully annealed (CGFA) samples by 10 to 20 %. Isothermal annealing at elevated temperatures between 90 and 630°С leads to a sharp decrease of Young’s modulus for annealing temperatures above 210°С. After annealing at 410°С, the value of E reaches its minimal value that is 35 % lower than E in CGFA samples (total change in E is about 47 % of the initial value). Further annealing at higher temperatures leads to an increase in Young’s modulus. It is shown, that the unusual behavior of Young’s modulus is caused by formation of the <111> axial texture in the SPD-treated samples which then is replaced by the <001> texture during the post-SPD heat treatment.
 N. Kobelev, E. Kolyvanov, Y. Estrin, Temperature dependence of sound attenuation and shear modulus of ultra fine grained copper produced by equal channel angular pressing, Acta Materialia, 56, 1473-1481 (2008).
 E.N. Vatazhuk, P.P. Pal-Val, L.N. Pal-Val, V.D. Natsik, M.A. Tikhonovsky, A.A. Kupriyanov, Low-temperature relaxation processes in a Cu-Nb nanostructured fiber composite, Low Temp. Phys. 35, 417-423 (2009).
 I.S. Golovin, P.P. Pal-Val, L.N. Pal-Val, E.N. Vatazhuk, Y. Estrin, The effect of annealing on the internal friction in ECAP-modified ultrafine grained copper, Solid State Phenomena 184, 289-294 (2012).
 P.P. Pal-Val, L.N. Pal-Val, Low-temperature internal friction and nanostructured metal stability, Metal Science and Heat Treatment 54, 234-238 (2012).
 H.M. Ledbetter, Elastic constants of polycrystalline copper at low temperatures. Relationship to single-crystal elastic constants, Phys. Stat. Sol. (a) 66, 477-484 (1981).
 Y.A. Burenkov, S.P. Nikanorov, B.I. Smirnov, V.I. Kopylov, Recovery of Young’s modulus upon annealing of nanostructured niobium produced through severe plastic deformation. Phys Solid State 45, 2119-2123 (2003).
 L.D. Landau, E.M. Lifshitz, Theory of Elasticity, Pergamon Press, Oxford, 1970, p. 43.
 S.L. Demakov, Y.N. Loginov, A.G. Illarionov, M.A. Ivanova, M.S. Karabanalov, Effect of annealing temperature on the texture of copper wire. Phys. Metals Metallogr. 113, 681-686 (2012).