Kinetics of hydrogen-induced reverse phase transformation in Y2Fe17 hard magnetic alloy

S.B. Rybalka1, E.V. Dodonova2
1Bryansk State Technical University, 50-letiya Oktyabrya boulevard 7, 241035 Bryansk, Russia
2Donetsk National Technical University, Artema Street 58, 83000 Donetsk, DPR
Abstract
Kinetics of hydrogen-induced reverse phase transformation, i.e. recombination process of decomposed of YH2 hydride phase and alpha-Fe phase of iron in initial phase of Y2Fe17 hard magnetic alloy has been studied. It has been established that, as the temperature increase from 650 to 750˚С, a reverse phase transformation significantly accelerates. The activation energy of phase transformation process has been determined from kinetic data (227÷383 kJ/mol) that it is correspond to the values of activation energy of the Fe atoms diffusion in R–T type alloys. It has been shown that the kinetics of hydrogen-induced reverse phase transformation in Y2Fe17 hard magnetic alloy is controlled by the Fe atoms diffusion to growing new Y2Fe17 phase centers.  
Received: 02 October 2014   Accepted: 21 November 2014
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