Based on a general classification and characteristic comparison of the existing models, a new model for non-catalytic gas-solid reactions is proposed and a general formulation for the model in terms of the solid conve...Based on a general classification and characteristic comparison of the existing models, a new model for non-catalytic gas-solid reactions is proposed and a general formulation for the model in terms of the solid conversion, X, is presented in mis paper. The model, referred to the generalized model, is demonstrated to be applicable to any solid reactant of general structure ranging from highly porous to nonporous materials. It is shown that the generalized model incorporates the grain and pore structure for a solid pellet and can be reduced to the grain and random pore models as extreme cases.展开更多
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 ...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.展开更多
基金Project supproted by University of Queensland, Australia.
文摘Based on a general classification and characteristic comparison of the existing models, a new model for non-catalytic gas-solid reactions is proposed and a general formulation for the model in terms of the solid conversion, X, is presented in mis paper. The model, referred to the generalized model, is demonstrated to be applicable to any solid reactant of general structure ranging from highly porous to nonporous materials. It is shown that the generalized model incorporates the grain and pore structure for a solid pellet and can be reduced to the grain and random pore models as extreme cases.
文摘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.