Transformation Kinetics on Mechanical Alloying

We propose and develop a model as an attempt to describe the local mechanism of mechanical alloying. This model is based on the observation of global parameters, such as the volumes of the various phases present in the material, and their transformations during the process. The model is applied to m...

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Detalhes bibliográficos
Autores: Vasconcelos, Igor Frota de, Figueiredo, Reginaldo Souza de
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2003
País:Brasil
Recursos:Universidade Federal do Ceará (UFC)
Repositorio:Repositório Institucional da Universidade Federal do Ceará (UFC)
Idioma:inglés
OAI Identifier:oai:repositorio.ufc.br:riufc/67738
Acesso em linha:http://www.repositorio.ufc.br/handle/riufc/67738
Access Level:acceso abierto
Palavra-chave:Mechanical alloying
Fe-Cu and Fe-N
MA models
Descrição
Resumo:We propose and develop a model as an attempt to describe the local mechanism of mechanical alloying. This model is based on the observation of global parameters, such as the volumes of the various phases present in the material, and their transformations during the process. The model is applied to milled Fe-Cu and Fe-N experimental results obtained in previous works (NanoStruct. Mater. 1999, 11, 935;1 NanoStruct. Mater. 1994, 4, 6852). In the milling of the Fe-Cu system, four stages, whose features are in accordance with experimental observation, are identified: (i) energy storage, (ii) initiation of reaction and rate increase, (iii) decrease of the reaction rate, and (iv) stationary stage. No energy storage stage is observed and no saturation is achieved in the milling of Fe-N system. Moreover, we propose a modification on the global kinetic law introduced in ref 12 on the basis of the different natures of Fe-Cu and Fe-N systems. This modification allows the extension of the validity of this law.