The mechanical properties of high-pressure die-casted parts are directly influenced by their microstructure. This article aims to evaluate the effect of the fast-shot speed on the structural component and overall microstructure for two geometrically different castings. The material used during experimental works is commonly known as the AlSi9Cu3(Fe) alloy. For experimental purposes, numerical simulations, microstructural and EDS analysis, the DAS index, length of eutectic Si plates and more were implemented. The simulations have shown the possibility of air entrapment in the filling chamber. Oxides, and consequently microporosity, were localized, which led to the selection of critical points of the casts for further observation and evaluation. With the use of the optical/scanning microscope and microhardness evaluation, the fast-shot speed value of 3.6 m.s⁻¹ was selected as the most advantageous.

The paper focuses on the research of hybrid aluminium castings produced by overcasting technology. This is an advanced technology for ensuring the lightness of castings by using the principle of overcasting a core with a porous cellular structure produced by foaming. Process parameters in the foaming phase of the material have a great influence on the resulting porous structure. The article focuses on controlling the influence of pressure during the foaming process on the resulting porosity and evaluating by X-ray tomograph and measuring the relative density. Variants using an initial pressure of 0.3 MPa appear to be the most satisfactory. The challenge of this technology is to ensure adequate bonding of the metals at the interface between the porous core and the solidified metal without penetrating the coating layer. For this reason, the surface treatment of foamed cores with various etchants has been proposed to disrupt the oxide layer on their surface. Macrographs of the uncoated sample and samples etched with 0.5% HF and 10% H3PO4 demonstrated the need for core surface treatment to prevent liquid metal penetration. EDX analysis confirmed the presence of AlPO4 at the core/casting interface in the treated sample.

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.

The paper focuses on the technological challenges posed by the production of experimental hybrid castings by overcasting technology. Theoretically, using this technology provides lower casting weight while maintaining positive mechanical properties and improves the energy absorption capability of the component. The effect of the pressure used during the foaming of the cores on the relative density of the metal foam component was experimentally evaluated. The challenge of the technology is the interface between the casting and the oxide coated core surface. Surface-treated cores were cast and their interfaces were observed microscopically. The experimental results showed a positive effect of the presence of AlPO4 in the interface to prevent the penetration of liquid metal into the pores of the foam core.

The paper deals with the possibilities of using alkali silicate based inorganic binders for automotive industry aluminium castings production. In recent years, inorganic binders are coming back to the foreground and their manufacturers are developing new processes, which are starting to progressively supersede organic binder systems. Paper describes known knowledge about classic alkali silicate binders with focus on hardening processes and on improving their technological properties. Trends from the area of development and the use new alkali silicate based inorganic binders are also shortly described. As part of the experimental work, specific methods of producing samples were developed, with the help of which properties such as disintegration were subsequently evaluated by measuring abrasion and residual strengths. Characteristics such as residual compressive strength or shear strength at different thermal loads were also evaluated. When comparing the laboratory results with the results of de-coring in real conditions, a high degree of correlation was achieved, which makes it possible to determine the optimal recipe/procedure for the production of geometrically complex cores.

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