Thermo-kinetic modelling of the giant Snoek effect in carbon-supersaturated iron

JOURNAL OF ALLOYS AND COMPOUNDS

卷:877

Article

Maugis, Philippe¹ 

[1] Aix Marseille Univ, IM2NP, CNRS, Marseille, France

关键词: Anelastic behaviour;    Internal friction;    Long-range ordering;    Carbon steels;   

DOI  :  10.1016/j.jallcom.2021.160236

来源: Elsevier

【 摘 要 】

Snoek relaxation in interstitial bcc solid solutions is the origin of the Snoek peak in frequency-dependent and temperature-dependent internal friction measurements. When applied to low-carbon steels, the internal friction profiles show a linear dependence of the peak height with carbon content. However, recent Monte Carlo simulations of frequency-dependent internal friction exhibited a non-linear giant peak height at high carbon contents. To investigate this effect in temperature-dependent internal friction, we developed a thermo-kinetic mean-field theory of the Snoek relaxation phenomenon. By taking into account the collective behaviour of the interstitial atoms, our theory predicts (i) a non-linear dependence of the peak height with composition when approaching the order-disorder transition of the alloy; (ii) a shift in the temperature of the peak; (iii) a composition-dependent activation enthalpy of the relaxation time. The theory is exemplified by the case of carbon-supersaturated iron. (c) 2021 Elsevier B.V. All rights reserved.

【 授权许可】

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