title: Metallographic assessment of Al-12Si high-pressure die casting escalator steps.
abstract: A microstructural characterization study was performed on high-pressure die cast specimens extracted from escalator steps manufactured from an Al-12 wt.% Si alloy designed for structural applications. Black and white, color light optical imaging and scanning electron microscopy techniques were used to conduct the microstructural analysis. Most regions in the samples studied contained globular-rosette primary α-Al grains surrounded by an Al-Si eutectic aggregate, while primary dendritic α-Al grains were present in the surface layer. This dendritic microstructure was observed in the regions where the melt did not impinge directly on the die surface during cavity filling. Consequently, microstructures in the surface layer were nonuniform. Utilizing physical metallurgy principles, these results were analyzed in terms of the applied pressure and filling velocity during high-pressure die casting. The effects of these parameters on solidification at different locations of the casting are discussed.
authors.affiliation: 1Consultant,2887 N. Southern Hills Drive,Wadsworth,IL 60083-9293,USA.
authors.forename: George Frederic
authors.initials: GF
authors.lastname: Vander Voort
authors.affiliation: 2Department of Materials Science and Metallurgical Engineering,Polytechnic School of Engineering,University of Oviedo,Campus of Gijón,Gijón,Asturias 33203,Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Suárez-Peña
authors.affiliation: 3Department of Materials Science and Metallurgical Engineering,The School of Mines,The University of Oviedo,Oviedo 33004,Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Asensio-Lozano