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

Wirginia Pilarczyk,Adam Zarychta

doi:10.1007/s10973-016-5633-1

Wirginia Pilarczyk, Adam Zarychta

https://doi.org/10.1007/s10973-016-5633-1

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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 Buhler 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.

Highlights

The ‘‘amorphous material’’ term is refer to solid state, with non-periodical atomic arrangement
On the basis of multiple tests, it can be concluded that amorphous alloys have new atomic configurations, which differ from crystalline alloys
The XRD patterns show broad hallo diffraction patterns, which indicate the amorphous nature of obtained metallic glasses (Fig. 2a, b)

Summary

Introduction

The ‘‘amorphous material’’ term is refer to solid state, with non-periodical atomic arrangement. The short range arrangement of atoms is the special feature of amorphous material atomic structure. The amorphous structure of materials could be described by topological disorder and chemical disorder. The first kind of disorder is a result of dispersion of distances arrangement of atoms, because of lack of repeatable geometric packing, whereas the chemical disorder is a result of local environment of each atoms [1, 2]. On the basis of multiple tests, it can be concluded that amorphous alloys have new atomic configurations, which differ from crystalline alloys. Due to the special structure, amorphous materials have different properties from conventional crystalline alloys. Amorphous materials have been determined by many characteristic such as useful magnetic properties, good mechanical properties or unique chemical properties. Intensive development of metallic glasses and afterwards bulk metallic glasses has caused new interest on glassy metals researches [3,4,5,6,7]

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