WETTING AND PREMELTING PHASE TRANSITIONS IN 43° <100> TILT GRAIN BOUNDARIES IN Fe-5at.% Si

E.I. RABKIN; L.S. SHVINDLERMAN; B.B. STRAUMAL

doi:doi:10.1051/jphyscol:1990194

Numéro		J. Phys. Colloques Volume 51, Numéro C1, Janvier 1990 Proceeding of the International Congress Intergranular and Interphase Boundaries in materials


Page(s)		C1-599 - C1-603
DOI		https://doi.org/10.1051/jphyscol:1990194

J. Phys. Colloques 51, C1-599-C1-603 (1990)
DOI: 10.1051/jphyscol:1990194

WETTING AND PREMELTING PHASE TRANSITIONS IN 43° <100> TILT GRAIN BOUNDARIES IN Fe-5at.% Si

E.I. RABKIN, L.S. SHVINDLERMAN et B.B. STRAUMAL

Institute of Solid State Physics, Academy of Sciences of the URSS, Chernogolovka, Moscow district 142432, U.R.S.S.

Abstract
Penetration of Sn and Zn along a 43° <100> tilt grain boundary (TiGB) in a body-centred cubic (bcc) Fe - 5 at.% Si alloy is studied in the temperature range of 652 - 975°C. Wetting transition of GB by the Sn-rich melt is observed at T_W = 810 ± 5°C. For Zn penetration along the GB, the wetting film is observed at all temperatures studied. The region behind the wetting film is observed to have an unusually high GB diffusivity of Zn (by two order of magnitude), followed by a region of "usual" GB diffusivity. The transition from usual to anomalous GB diffusivity D'δ, where D' is the GB diffusion coefficient and δ is the GB width, takes place at the concentration C_bt. The value C_bt is independent of the annealing time, but depends strongly on the temperature. Such a phenomenon may be explained in terms of the so-called premelting phase transition "GB thin wetting film on the boundary".