Solidificação, microestrutura e propriedades mecânicas da liga de alumínio 6061 com 1,4%p Fe processada por conformação por spray e extrusão a quente

Abstract

The 6xxx series aluminum alloys are wrought alloys which belongs to the MgSi class and can be heat treated, have a good workability and a good mechanical resistance / weight ratio. A great challenge is to avoid impurity elements in the aluminum alloys, like iron during the recycling cycle. The main effects of this type of elements are the formation of a coarsed microstructure and the nucleation of undesired intermetallic phases with a morphology that acts as stress concentrations and decreases the mechanical properties. The aluminum alloys that contains Fe are considered complex due to a range of intermetallic compound that can be formed. Due to the chemical composition of this alloy, this work will give some attention to intermetallic phases formed with low Fe content, like α-Al8Fe2Si phase and β-Al9Fe2Si2 phase. This study analyzed the solidification, microstructure and mechanical properties of an AA6061 aluminum alloy with 1.4%wt. of iron content produced by spray forming and hot extrusion, with the purpose of developing an recycling route that allows mechanical processing of the aluminum alloys with high Fe contamination. During the analysis of solidification and microstructure, it was noticed that the spray forming process change the alloy’s solidification path, also altering the morphology of the present phases. The mechanical characterization allowed the understanding of the effects caused by the contamination of iron on the mechanical properties of the alloy studied.