The influence of heat treatment on the structure and thermal properties of metallic glasses

Abstract

This paper presents the structure and chosen properties of Fe-based ribbons with specified composition, after casting and heat treating. The aim of this work was to produce amorphous ribbons and study the influence of heat treatment on the structure and thermal properties before and after annealing. The base alloy ingot was prepared by induction melting of pure Fe, Co, B, Si and Nb elements in argon atmosphere. Then, the station for ultra-fast cooling of molten alloy with high vacuum pumps, designed for the production of metallic glasses in the form of ribbons by Bühler Melt Spinner SC was used. Also, the X-ray diffraction analysis system PANalytical X’Pert PRO was used. As-cast ribbons and metallic glasses after annealing were examined by differential scanning calorimetry (DSC) method, with the use of DSC822 Mettler Toledo. Annealing was done at different temperature. On the basis of obtained dependence, the glass transition temperature (Tg), onset crystallization temperature (onset—Tx) and peak crystallization temperature (peak—Tp) were determined. The supercooled liquid region (ΔTx), specific heat and the crystallization enthalpy (ΔH) were calculated as well. The microscopic observation of cross section of ribbons was carried out by means of the Zeiss Supra 35 scanning electron microscope. Based on experimental data, the discussion on the correlation between thermal properties, structure, annealing and future application was carried out.