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Investigation and Modelling of Glass Forming Ability and properties of Fe-Based Amorphous Materials

Институт экотехнологий и инжиниринга (ЭкоТех)
Кафедра металловедения цветных металлов (МЦМ)
Академическая группа
Научный руководитель
PhD, Assoc Prof, Alexander Churyumov
Название тезиса
Investigation and Modelling of Glass Forming Ability and properties of Fe-Based Amorphous Materials

Bulk metallic glasses have promising properties and are considered to be the replacement of some alloys which are used for various applications. A novel approach was used that allowed us to enhance Glass-Forming ability (GFA) of Fe-Based amorphous alloys with high saturation magnetization. A new Fe-Based amorphous material with high glass forming ability Fe 82-x  Co Nb 2 B 8 P 4 Si 2 C 1 Al 1 (where x = 0, 2, 4, 6, 8, 10 at.%) was produced by minor additions of Co content. The effect of niobium and cobalt on glass forming ability and magnetic properties, respectively, were investigated. Amorphous alloys in the shape of ribbons with average thickness of 25μm are obtained successfully by means of spin casting. XRD graphs without the addition of niobium content showed sharp peaks i.e. Bragg's Peaks, means every sample except one with 2 at.% Co content, was crystalline or in nano crystalline form. Whereas XRD graphs with 2 at. % Nb content showed fully amorphous peaks with no signs of Bragg's Peaks. DSC results with Nb addition demonstrated the increase in the Crystallization temperature (T x ) with increase in cobalt content, starting from 683 K to 753 K i.e.peaks are shifting towards right. Coercivities have shown some dramatic changes , just by adding 2 at. % Nb in the melt. Table 1 is showing the comparison of coercivities between different alloys, e.g. the alloy  Fe 78 Co Nb Si Al 1 have shown significant changes at 200 Hz.

Its value reduced to about 32 A/m, while for the same alloy but without addition of Nb i.e. alloy  Fe 80 Co 4 P 4 B 8 Si 2 C 1 Al 1 has shown very large value of Coercivity i.e. 95 A/m. Figure 1 is showing different values of Saturation Magnetization  (J s ).

It can be seen from the figure that the trend, of saturation magnetization with increase in cobalt content, is increasing. Maximum (Js) Obtained for the alloy of Fe 74 Co 8 Nb 2 P 4 B 8 Si 2 C 1 Al 1 is 1.51 T, and the average value of saturation magnetization is around 1.45 T.