Microstructure and properties of semi-solid aluminum alloys: A literature review

Semi-solid processing of aluminum alloys is a well-known manufacturing technique able to combine high production rates with parts quality, resulting in high performance and reasonable component costs. The advantages offered by semi-solid processing are due to the shear thinning behavior of the thixotropic slurries during the mold filling. This is related to the microstructure of these slurries consisting of solid, nondendritic, near-globular primary particles surrounded by a liquid matrix. This paper presents a review on the formation of this nondendritic microstructure, reports on the different proposed mechanisms that might be responsible, and illustrates the relationship between microstructure and properties, in particular, tensility, fatigue, wear, and corrosion resistance

Novel recycling system of aluminum and iron wastes-in-situ Al-Al3Fe functionally graded material manufactured by a centrifugal method

In this study, the concept of novel recycling system using waste Al and Fe is described. Taking advantage of the fact that due to its cyclic usage, aluminum scrap unavoidably contains iron and steel wastes, an in-situ Al-Al 3 Fe functionally graded material (FGM) is planned to be fabricated. A centrifugal method is applied to a model master alloy, Al-10 mass% Fe, obtained from virgin materials, the content of which is decided from the liquidus temperature. The resulting product is a thick-walled tube having a graded distribution of second phase particles in the Al matrix. It has been established that the shape of the particles varies depending on their position along the radial direction. The second phase is confirmed to be a stable Al 3 Fe intermetallic compound. Thin plates of Al-Al 3 Fe having homogeneously distributed Al 3 Fe particles, considering both the composition gradient and the particle morphology, were machined from the thick-walled Al-Al 3 Fe FGM tube and their mechanical properties measured. Based on the experimental observations, the potential and the advantages of the Al-Al 3 Fe alloy as a recyclable eco-FGM are discussed