Technológ - Ročník 15.; Číslo 2/2023

Permanent URI for this collectionhttps://drepo.uniza.sk/handle/hdluniza/838

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    Hodnotenie vplyvu technologických parametrov na mikroštrutúru vysokotlakových odliatkov
    (Žilinská univerzita v Žiline, 2023) Medňanský, Martin; Brůna, Marek; Matejka, Marek
    A number of technological parameters influence the mechanical properties of a high pressure die casting. The aim of the presented paper was to perform microstructural analysis of AlSi9Cu3(Fe) alloy casting fabricated with high-pressure die casting (HPDC) technology. Several castings with varying casting parameter – maximum plunger speed vmax were cast. In pre-selected critical spots, the effect of vmax was observed on the shape and size of the structural components, where at lower vmax the eutectic Si shortened in length and thickened. 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 being present in both modifications – oblong grains and globular ternary eutectic. There was no significant change in microhardness of α(Al) phase found, that would be caused by the varying vmax
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    Oxidické vrstvy a bifilmy v odliatkoch hliníkových zliatin
    (Žilinská univerzita v Žiline, 2023) Galčík, Marek; Brůna, Marek
    Surface of aluminium alloy melt is covered by an oxide layer when it is in contact with the surrounding atmosphere. When the oxide layer is retained on the surface of the melt it prevents the melt by hydrogen saturation. The oxide layer is harmful when it is submerged into the melt. The work focuses on the influence of the melt velocity on the bifilm formation, morphology of oxide layers and their influence on the porosity and filling the mold cavity.