Microstructural analysis of a1-mg-si-zn alloy

As a part of an overall effort to develop a new A1-alloy appropriated for structural applications, a characterization research was directed towards the development of microstructure and their relationship with heat treatment. The A1-Mg-Si-Zn was chose for that purpose due to the presence of precipitates in α-A1 matrix and at grain boundaries, capable to get an excellent relationship between hardness and mechanical resistance. With regards to microstructure, this was characterized in the as-cast and as-aged condition. This treatment was carried out in two stages, the first one at 450ºC during 3 hr which correspond to homogenization treatment and the second one, the ageing treatment at 160 ºC 1hr. Results of microstructure characterization in the ascast ingots showed the α-A1 dendrites, and in addition the presence of a binary eutectic and particles of Mg₇Zn₃ type in interdendritic regions. The eutectic and particles were modified by the aged treatment. Transmission electron microscopic observations carried out in specimens with and without heat treatments showed a uniform distribution of precipitates with different morphologies like cubic, spherical and platelet; in the matrix, which were no detected during the scanning electron microscope observations.

• Autores: Valadez, Sergio; Zanatta Alarcón, Adrianni; Robles Casolco, Said; Valdéz Rodríguez, Socorro
• Tipo de recurso: Article of journal
• Fecha de publicación: 2010
• Institución: Universidad Nacional de Colombia
• Repositorio: Universidad Nacional de Colombia
• Idioma: spa
• OAI Identifier: oai:repositorio.unal.edu.co:unal/37579
• Acceso en línea: https://repositorio.unal.edu.co/handle/unal/37579; http://bdigital.unal.edu.co/27663/
• Palabra clave: Microstructure; eutectic; precipitates; heat treatment.
• Rights: openAccess
• License: Atribución-NoComercial 4.0 Internacional