Determination of thermodynamic stability of FeB monoboride

Filonenko, N.Yu. and Galdina, A.N. (2019) Determination of thermodynamic stability of FeB monoboride. Journal of Physics and Electronics, V. 27 (№ 2). pp. 69-76. ISSN 2616-8685

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Abstract

In this paper we investigate the phase composition and phase transformations in the Fe-B system alloys with boron content in the range of 9.0–15.0 wt.%. We use microstructural, X-ray diffraction, differential thermal and durometric analyzes to determine the physical properties of the alloys. The experimental findings show that in the as-cast alloy structure there is Fe5B3 phase in small quantities along with FeB monoboride and Fe2B boride. The Fe5B3 phase is formed as a result of the peritectic reaction L+FeB→Fe5B3 at the temperature of 1680 K. The eutectic transformation L→Fe5B3+Fe2B occurs in the boron concentration range of 8.8–10.5 wt.%. After annealing of the Fe-B alloys at the temperature of 1473 K and cooling with the rate of 102 K/s we observe the occurring of the Fe5B3 phase. To spot an opportunity of the secondary monoboride formation in the alloys under consideration, we calculate the thermodynamic characteristics of stability of the system. Accounting for the contribution of the first degree approximation of high-temperature expansion of thermodynamic potential of FeB iron monoboride in a Fe-B binary alloy enables us to study its thermodynamic stability. It is shown that stability decrease of FeB at 1423 K allows suggesting that at this temperature the phase transformation occurs and this fact correlates to the differential thermal analysis results.

Item Type:	Article
Additional Information:	Ця стаття також є у NAP-2018, 2018 IEEE 8th International Conference on Nanomaterials: Applications & Properties. - Одеса, 2018. - С. 1-4
Uncontrolled Keywords:	Fe-В alloys; FeB iron monoboride; thermodynamic stability.
Subjects:	Physics
Divisions:	Departments > Department of Medical and Biological Physics and Informatics
Depositing User:	Аліна Чеботарьова
Date Deposited:	20 Aug 2020 11:35
Last Modified:	01 Sep 2020 08:48
URI:	http://repo.dma.dp.ua/id/eprint/5622

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