Two types of approach to the simulation of Snoek-type relaxation were used to explain experimental results on Fe-Al-C and Fe-C-Cr alloys. The first approach was to calculate all of the octahedral positions which were available to interstitial atoms, with various numbers of substitutional atoms in the first coordination shell, and to simulate the loss maximum as the sum of all of the partial peaks which corresponded to the above interstitial positions. The second approach took account of all of the pairwise interatomic interactions between solute atoms in a few coordination shells; due to their interatomic elastic and chemical interactions. The change in activation energy for the diffusion under stress of interstitial atoms in that case was not a linear function of the substitutional concentration in solution. Both physical models (short-range and long-range interatomic interactions) for the Snoek-type relaxation in quenched ternary alloys were considered from the viewpoint of the distance of interatomic interaction. It was shown that, unlike the second approach, the first type of calculation was reasonable only for relatively low-alloy solid solutions. Decomposition and ordering changed the atomic distribution parameters in body-centered cubic solid solutions and led to a corresponding change in the Snoek relaxation parameters.

Interstitial Distribution in Fe-Al and Fe-Cr Quenched and Aged Alloys - Computer Simulation and Internal Friction Study. I.S.Golovin: Journal of Alloys and Compounds, 2000, 310[1-2], 356-62