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

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.