Behavior of AlxMgFeZn-alloy through microhardness, microstructure, thermal treatment and electrodissolution

Microstructural changes induced by aged treatment shown a connection between differences of microhardness and electrodissolution. AlxMgFeZn alloys were prepared by metal mold casting method in order to diminish the process cost generating an alloy with homogenous microstructure and less casting porosity. In addition, was correlated the influence of chemical composition with the thermal treatment on the electrochemical dissolution or electrodissolution. With all this in mind, the AlxMgFeZn alloy has been studied by means of microhardness, X-ray diffraction, scanning electron microscopy, and short-term electrochemical test. The formation of Mg3Zn3Al2 precipitate phase was identified for two conditions, the first one is when the chemical composition of magnesium is upper to 5.49% in as-cast condition and the second one is influenced by the thermal treatment of aging. In addition, the microhardness and electrochemical dissolution has been influenced by the presence and quantity of the Mg3Zn3Al2 phase. The chemical composition of magnesium alloying modifies the microstructure, increases the content of Mg3Zn3Al2 phase and, provides a localized dissolution on the AlxMgFeZn alloy surface.