Strain-Induced Interaction of Dissolved Atoms and Mechanical Relaxation in Solid Solutions. A Review

Abstract

The interaction of dissolved atoms affects the arrangement and energies of the atoms and the asymmetry of the distortion field around a dissolved atom and thereby influences the relaxation processes in solid solutions. This review describes the strain-induced model of atom interaction along with selected examples of the model's applications for analysis of the connection between dissolved atom interaction and peculiarities of mechanical relaxations in interstitial and interstitialsubstitutional solid solutions. The strain-induced interaction is long-range, oscillating, anisotropic, and, in some solid solutions, very strong. In all the investigated cases some coordination shells show attraction. The dependence on distance is determined mainly by the type of crystal lattice; for one type of crystal lattice the dependence is determined by the type of interstitials. The energies of interstitial-interstitial (i-i), interstitial-substitutional (i-s) and substitutional-substitutional (s-s) interaction are calculated for many bcc and fcc metal solid solutions. It is found that a straininduced interaction must be supplemented by a short-range screened Coulomb repulsion in the case of i-i interaction and by a short-range 'chemical' interaction in the case of i-s interaction.The model was previously used in the analysis of: (1) the Cr concentration dependence of the carbon Snoek peak temperature in Fe-Cr-C alloys; (2) the influence of Al ordering on the carbon Snoek peak in -Fe; (3) the effect of plastic deformation on the Finkelstein-Rosin carbon peak in austenitic steels; and (4) the calculation of hydrogen internal friction peaks in Nb and Ta. It is demonstrated that the described model can explain many peculiarities of mechanical relaxations in interstitial solid solutions as observed by internal friction (mechanical spectroscopy).

Internal Friction and Microstructure of Ti and Ti-Mo Alloys Containing Oxygen

“…It is tacitly assumed here, that the internal friction peaks might be estimated as single relaxation processes. Nonetheless, more detailed analysis should take into account the interaction between interstitial atoms [22][23][24][25][26][27][28][29][30]48], the anisotropy effect of Snoek peak [18][19][20][21], and grain size.…”

“…The internal friction spectra were resolved into constituent Debye peaks corresponding to different relaxation processes. The analysis of secondary features of internal friction peaks caused by the interaction between interstitial atoms and substitutional-interstitial pairs [22][23][24][25][26][27][28][29][30] as well as the anisotropy effect of Snoek relaxation [18][19][20][21], and the type of stress applied are outside the scope of the present study. Notwithstanding, it is now generally recognized that the secondary features are responsible for the broadening of Snoek peak, the variation in peak's temperature [21][22][23][24][25][26][27][28][29][30] and peak's height [18][19][20][21].…”

“…Mechanical spectroscopy [6][7][8][9][10][11][12][13][14] provides important information about the behavior of interstitial atoms in binary and ternary alloys such as the concentration of dissolved interstitial atoms in solid solution, diffusivity, solubility limit [6,[14][15][16][17][18][19][20][21], precipitation, and their interaction phenomena caused by interaction between relaxing entities [22][23][24][25][26][27][28][29][30], short-and longrange interaction of mobile point defects with dislocations [31][32][33][34][35][36][37][38][39][40][41], and strain aging. In general, the time-invariant harmonic stress field imposed on a sample containing interstitial atoms dissolved in solid solution yields splitting of free-energy levels of different elastic dipoles' orientations [17].…”

Relationship Between Bake Hardening, Snoek-Köster and Dislocation-Enhanced Snoek Peaks in Coarse Grained Low Carbon Steel

“…The interaction between the substitutional and interstitial atoms in ferrite and austenite affects the behavior of carbon atoms [79][80][81][82][83][84][85][86][87]. The interaction of substitutional atoms in solution with carbon atoms also affects bake hardening.…”

Hilbert-Twin – A Novel Hilbert Transform-Based Method To Compute Envelope Of Free Decaying Oscillations Embedded In Noise, And The Logarithmic Decrement In High-Resolution Mechanical Spectroscopy HRMS

“…In mechanical spectroscopy studies, it is often difficult to access experimental fine details of mechanical losses, such as the asymmetrical broadening of the Snoek-Köster peaks in deformed Fe-C alloys [1,2] and various steels containing martensite, hardly discernable overlapping relaxation peaks [3], phase transition peaks, other non-linear mechanical losses, transient internal friction peaks, etc. Accurate analysis of these mechanical losses is critical for the understanding of the physical mechanisms that govern internal friction peaks in metals and alloys.…”