Laws of Thermally Induced Formation of Phases in alpha-Fe with a Titanium Coating upon Isochronous Annealingsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:Mossbauer spectroscopy and X-ray diffraction were used to study thermally induced processes of diffusion and phase transformations in nonequilibrium layered systems Fe (10 mu m)-Ti (2 mu m) and Fe(0.966)Ti(0.034) (10 mu m)-Ti (2 mu m) upon isochronous annealing. The relative concentrations of phases have been determined and the sequence of phase transformations in the near-surface layers and in the bulk of samples have been established. It has been shown that the interdiffusion of components results in the formation of intermetallic compounds FeTi and Fe(2)Ti in the contact layer between the coating and the substrate. Titanium diffusing into the matrix of the substrate forms a solid solution on the basis of alpha-Fe. The kinetics of phase formation in alpha-Fe and in the Fe(0.966)Ti(0.034) alloy with a titanium coating occurs by the same mechanism without fundamental differences; however, the process of the formation of phases in the alloy occurs at higher temperatures. The difference is only in the phase relationship at different stages of annealing. A correlated change in the average value and dispersion of the distribution function of the hyperfine magnetic field at the (57)Fe nuclei in the alpha-Fe(Ti) solid solution with a change in the impurity concentration has been found. A method has been suggested for determining the concentration of substitutional impurity in the alpha-Fe solid solution from the average value of the hyperfine magnetic field (H) over bar (n) at (57)Fe nuclei. In the process of sequential thermal anneals, both systems remain layered and consist of the solid solution of Ti in alpha-Fe with the limiting concentration on the substrate side, and of an intermetallic compound Fe(2+x)Ti(1-x) enriched in iron on the coating side.