Technológ - Ročník 15.; Číslo 1/2023

Permanent URI for this collectionhttps://drepo.uniza.sk/handle/hdluniza/797

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    Accompanying phenomena during casting of aluminium alloys
    (University of Žilina, 2023) Galčík, Marek; Brůna, Marek; Medňanský, Martin
    An oxide layer is formed on the surface of a molten aluminium alloy when it is exposed to the surrounding atmosphere. The oxide layer on the surface of the melt is not harmful. The problem occurs when it is entrained into the melt volume and solidifies in the casting. The paper deals with the formation of the oxide layer, its types and the formation of a double oxide layers.
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    Štruktúra hliníkových zliatin pre vysokotlakové odlievanie
    (University of Žilina, 2023) Medňanský, Martin; Brůna, Marek; Matejka, Marek
    The aim of the presented paper was to carry out a review of the internal structure of alloys used for high pressure die casting (HPDC) and to experimentally perform a structural analysis of AlSi9Cu3(Fe) alloy. Several castings with varying casting parameter – maximum plunger speed vmax were cast. In pre-selected critical locations, a change in porosity was observed with the change of the speed, and the casting samples with vmax = 2 and 3 m∙s-1 showed the lowest porosity. The effect of vmax was also observed on the shape and size of the structural components, where at higher vmax the eutectic Si grew in length and decreased in thickness. EDS analysis determined found intermetallic phases to be α-Al(Fe,Mn,Cr)Si in the shape of a rhombic dodecahedron with sizes as small as 2 µm and Al2Cu occurring in both modifications – oblong grains and globular ternary eutectic.