The Internal Friction of Single Crystals, Bicrystals and Polycrystals of Pure Magnesium

W. B. Jiang; Q. P. Kong; L. B. Magalas; Q. F. Fang

Download PDF - The Internal Friction of Single Crystals, Bicrystals and Polycrystals of Pure Magnesium, Opens in new tab

ArticleOriginal scientific text

Title

ENG

POL

The Internal Friction of Single Crystals, Bicrystals and Polycrystals of Pure Magnesium

Authors ¹, ¹, ², ¹

Affiliations

Key Laboratory of Materials Physics, Institute of Solid State
AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków, Poland

Abstract

ENG

POL

The internal friction of magnesium single crystals, bicrystals and polycrystals has been studied between room temperature and 450°C. There is no internal friction peak in the single crystals, but a prominent relaxation peak appears at around 160°C in polycrystals. The activation energy of the peak is 1.0 eV, which is consistent with the grain boundary self-diffusion energy of Mg. Therefore, the peak in polycrystals can be attributed to grain boundary relaxation. For the three studied bicrystals, the grain boundary peak temperatures and activation energies are higher than that of polycrystals, while the peak heights are much lower. The difference between the internal friction peaks in bicrystals and polycrystals is possibly caused by the difference in the concentrations of segregated impurities in grain boundaries.

Badania tarcia wewnętrznego w monokryształach, bikryształach i polikryształach magnezu przeprowadzono w zakresie temperatur między temperaturą pokojową a 450°C. W monokryształach magnezu nie występuje pik tarcia wewnętrznego, ale wyraźny pik relaksacyjny pojawia się przy około 160°C w polikryształach. Energia aktywacji piku wynosi 1,0 eV, co jest zgodne z energią autodyfuzji Mg przez granice ziaren. Z tego względu pik tarcia wewnętrznego występujący w polikryształach można przypisać relaksacji granic ziaren. W przypadku trzech badanych bikryształów temperatury pików pochodzących od granic ziaren i ich energie aktywacji są wyższe niż w przypadku polikryształów, ale wysokości tych pików są znacznie niższe. Różnica między pikami tarcia wewnętrznego w bikryształach i polikryształach jest prawdopodobnie spowodowana przez różnicę stężeń zanieczyszczeń segregujących na granicach ziaren.

Keywords

ENG

POL

magnesium, single crystal, bicrystal, polycrystal, grain boundary, internal friction

T. S. Ke, Experimental evidence of the viscous behavior of grain boundaries in metals, Phys. Rev. 71, 533-546 (1947).
W. B. Jiang, P. Cui, Q. P. Kong, Y. Shi, M. Winning, Internal friction peak in pure Al bicrystals with <100>tilt boundaries, Phys. Rev. B 72, 174118 (2005).
Y. Shi, W. B. Jiang, Q. P. Kong, P. Cui, Q. F. Fang, M. Winning, Basic mechanism of grain-boundary internal friction revealed by a coupling model, Phys. Rev. B 73, 174101 (2006).
W. B. Jiang, Q. P. Kong, D. A. Molodov, G. Gottstein, Compensation effect in grain boundary internal friction, Acta Mater. 57, 3237-3331 (2009).
W. B. Jiang, Q. P. Kong, P. Cui, Q. F. Fang, D. A. Molodov, G. Gottstein, Internal friction in Al bicrystals with <111>tilt and twist grain boundaries, Phil. Mag. 90, 753-764 (2010).
W. B. Jiang, Q. P. Kong, P. Cui, Further evidence of grain bound-ary internal friction in bicrystals, Mater. Sci. Eng. A 527, 6028-6033 (2010).
Q. P. Kong, W. B. Jiang, P. Cui, Q. F. Fang, Recent investigations on grain boundary relaxation, Sol. St. Phen. 184, 33-41 (2012).
X. S. Hu, Y. K. Zhang, M. Y. Zheng, K. Wu, A study of damping capacities in pure Mg and Mg-Ni alloy, Script Mater. 52, 1141-1145 (2005).
X. S. Hu, X. J. Wang, X. D. He, K. Wu, M. Y. Zheng, Low fre-quency damping capacities of commercial pure magnesium, Trans. Nonferrous Met. Soc. China 22, 1907-1911 (2012).
G. D. Fan, M. Y. Zheng, X. S. Hu, C. Xu, K. Wu, I. S. Golovin, Effect of heat treatment on internal friction in ECAP processed commercial pure Mg, J. Alloy Compd. 549, 38-45 (2013).
G. D. Fan, M. Y. Zheng, X. S. Hu, C. Xu, K. Wu, I. S. Golovin, Improved mechanical property and internal friction of pure Mg processed by ECAP, Mater. Sci. Eng. A 566, 588-594 (2012).
C. Esnouf, G. Fantozzi, Medium temperature internal friciton in high purity f.c.c. and h.c.p metals, J. Phys. C5, 445-450 (1981).
M. L. Nó, A. Oleaga, C. Esnouf, J. San Juan, Internal friction at medium temperatures in high purity magnesium, Phys. Stat. Sol. (a) 120, 419-427 (1990).
Z. Trojanov, B. Weidenfeller, P. Lukae, W. Riehemann, M. Stank, Anelastic properties of nanocrystalline magnesium, in: M. J. Zehetbauer, R. Z. Valiev (Eds.) Nanomaterials by se-vere plastic deformation, Wiley-Vch Veriag GmbH, Weinheim, 413-419 (2004).
A. S. Nowick, B. S. Berry, Anelastic Relaxations in Crystalline Solids, Academic Press, New York, London, 1972.
H. J. Frost, M. F. Ashby, Deformation-mechanisms Maps, Perg-amon Press, Oxford, 1982.
K. L. Ngai, Relaxation and Diffusion in Complex Systems, Springer, New York, 2011.
L. B. Magalas, Mechanical spectroscopy - Fundamentals, Sol. St. Phen. 89, 1-22 (2003).
K. L. Ngai, Y. N. Wang, L. B. Magalas, Theoretical basis and general applicability of the coupling model to relaxations in coupled systems, J. Alloy Compd. 211-212, 327-332 (1994).
L. B. Magalas, Snoek-Köster relaxation. New insights - New paradigms, J. Phys. IV 6, 163-172 (1996).

Title

The Internal Friction of Single Crystals, Bicrystals and Polycrystals of Pure Magnesium

Affiliations

Abstract

Keywords

Bibliography