Affiliation:
1. Udmurt Federal Research Center, Ural Branch, Russian Academy of Sciences
Abstract
The effect of the action of temperature on the structure and phase composition of anFe3C/Fe7C3/P-phase/Cam composite obtained by mechanosynthesis of Fe–75 at % C has been studied by the methods of X-ray diffraction, Mössbauer spectroscopy, thermogravimetric analysis, and differentialscanning calorimetry. It is shown that the structural and phase changes at heating have a multistage character.In the temperature range 315–400°C crystallization of the paramagnetic P-phase with generation of Fe3Cand/or Fe7C3 occur. In the course of heating to higher temperatures, complete decomposition of carbideFe7C3 (in the range 450–550°C) and partial decomposition of Fe3C (at 600°C and above) are observed. Aftercooling from 800–1000°C the mechanocomposite consists of α-Fe, cementite Fe3C, and graphite. The phasetransformations are accompanied by the processes of composite oxidation with the formation of Fe3O4 oxide and its subsequent reduction. The P-phase is a disorded amorphous carbide Fe1 – xCx, which is characterized by magnetic ordering at the temperature of liquid nitrogen.
Publisher
The Russian Academy of Sciences
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