TITLE:
Growth Kinetics of Nd2Fe14B Phase during Hydrogen-Induced Reverse Phase Transformation in Nd2Fe14B Type Nanocrystalline Magnetic Alloy
AUTHORS:
Sergey Borisovich Rybalka
KEYWORDS:
Intermetallics, Growth Kinetics, Permanent Magnets, Gas–solid Reactions
PACS numbers: 64.70.Kd, 68.35.Fx, 66.30.-h
JOURNAL NAME:
Materials Sciences and Applications,
Vol.2 No.8,
August
24,
2011
ABSTRACT: The influence of hydrogen pressure on kinetics of growth of Nd2Fe14B phase during hydrogen-induced reverse phase transformations in the industrial Nd2Fe14B hard magnetic alloy has been studied. It has been determined that, as the temperature and the initial hydrogen pressure increase, a reverse phase transformation significantly accelerates. It has been shown that the kinetics of the reverse phase transformation is controlled by the Fe atoms diffusion and that the rate growth of new Nd2Fe14B phase increase with increase of initial hydrogen pressure. On the base of the Kolmogorov kinetic theory the kinetic equation describing influence of initial hydrogen pressure on the isothermal kinetic diagram for this transformation has been obtained.