In this paper, a naturally pressurized gating system has been designed to reduce the turbulence of the melt during casting. The influence of gate dimensions, foam filters, a trident gate and a vortex element were evaluated. Their effect on melt velocity, flow characteristics, number of oxides, casting properties and mechanical properties were observed. ProCAST Simulation software v.2023 and a water flow test were also evaluated to assist in the experimental evaluation of the castings. Melts showed a relationship between melt velocity and porosity of castings. Quantitative evaluation of the surface porosity showed a trend of decreasing porosity with decreasing melt velocity. The greatest reduction in the melt velocity was achieved by a M4 design, which was associated with the highest reduction in the oxides. The pores analyzed proved the presence of oxide layers on their inner surface and a possible theory of pore formation when the initiator of porosity is entrained double oxide layers. The best metal yield was achieved with M1, but the difference between M2 and M4 was negligible (2–5% yield difference), so it can be stated that the beneficial effect of the M4 design in providing the best quality castings is not negated by the increase in metal yield.

Corrosion-resistant steels form an important group of structural materials who’s mechanical and corrosion-resistant properties are an irreplaceable part of the engineering industry. Despite their designation as "stainless steel", it is necessary to consider that even these steels can be subject to various types of corrosion attack under certain conditions. The article presents the effect of a controlled protective nitrogen atmosphere on X5CrNi18-10 steel, which is used to produce auxiliary components in the automotive industry. Steel X5CrNi18-10 is not only subject to corrosion after a short time (2hr) in a nitrogen atmosphere, at a temperature of 570 to 630°C, but at the same time the mechanical properties also change. Nitrogen atmosphere is used in heat treatment in automotive and X5CrNi18-10 steel is often used in these conditions as an auxiliary material, e.g. base grid. One test for X5CrNi18-10 steel was that the samples were exposed to a nitrogen atmosphere at various temperatures and then the agreed yield stress Rp0.2, hardness and microstructure were evaluated. The second test was the evaluation of the frame made of the given steel at 630 °C. The testing took place in a continuous furnace. Temperatures above 500 °C significantly changes the material's features.

The paper compares changes in the structure and mechanical properties due to the synergistic effect of alloying elements Zr and Ti. It is assumed that by increasing the content of Zr and Ti in the aluminium alloy, better mechanical properties will be achieved. Paper focuses on description of the differences between the samples casted into the shell mold and the metal mold. Main difference between mentioned molds is a different heat transfer coefficient during pouring, solidification and cooling of the metal in the mold. The main goal was to analyse the influence of Zr and Ti elements and compare the mechanical properties after the heat treatment. Curing and precipitation aging were used during the experiment. The effect of the elements on AlSi7Mg0.3 alloy created differences between the excluded Zr phases after heat treatment. Evaluation of the microstructure pointed to the decomposition of large predominantly needle Zr phases into smaller, more stable formations.

This article describes how different heat treatment methods affect the mechanical properties of AlSi7Cu0.5Mg. This article offers a new perspective on the topic of heat treatment analysis. AlSi7Cu0.5Mg alloy has a specific chemical composition due to its lower titanium and silicon content. It is still an experimentally tested alloy, intended for the production of high-strength castings in automotive applications. Although we are generally familiar with heat treatment methods for aluminum alloys, in the present case, we did not know the exact effect of artificial aging on the mechanical properties of AlSi7Cu0.5Mg. Five heat treatment regimes at temperatures of 160; 180; 200; 220 and 240 °C were monitored by removing the samples from the furnace at specified time intervals ranging from 30 min to 8 h. The solution treatment was the same for all samples (540 °C, 4 h and 80 °C water). The aim was to find out at what the highest hardness, strength, ductility, yield strength and metallographic yield strength were which could be obtained. The best properties were presented by the alloy which was artificially aged at 180 °C for 60 min. The topic and research on aluminum alloys in general are still relevant because in industrial practice and automotive applications, Al alloys are irreplaceable.

The article focused primarily on comparing the achieved mechanical results for AlSi7Mg0.3Cu0.5Zr and AlSi7Mg0.3Cu0.5Zr0.15Ti experimental alloys. Experimental variants with the addition of Zr ≥ 0.05 wt. % demonstrated the ability of Zr to precipitate in the form of Al3Zr or AlSiZr intermetallic phases. Zr precipitated in the form of long smooth needles with split ends. When evaluating the thermal analyses, the repeated peak was observed already with the initial addition of Zr in the range of approximately 630 °C. It was interesting to observe the increased interaction with other intermetallic phases. EDX analysis confirmed that the individual phases are based on Cu, Mg but also Fe. Similar phenomena were observed in experimental alloys with a constant addition of Zr and a gradual increase in Ti by 0.1 wt. %. A significant change occurred in the amount of precipitated Zr phases. A more significant increase in mechanical properties after heat treatment of AlSi7Mg0.3Cu0.5Zr experimental alloys was observed mainly above the Zr content ≥ 0.15 wt. % Zr. The improvement of yield and tensile strength over the AlSi7Mg0.3Cu0.5 reference alloy after heat treatment was minimal, not exceeding 1 %. A more significant improvement after heat treatment occurred in modulus of elongation with an increase by 6 %, and in hardness with an increase by 7 %. The most significant drop occurred in ductility where a decrease by 31 % was observed compared to the reference alloy. AlSi7Mg0.3Cu0.5Zr0.15Ti experimental alloys, characterized by varying Ti content, achieved a more significant improvement. The improvement in tensile strength over the AlSi7Mg0.3Cu0.5 reference alloy after heat treatment was minimal, not exceeding 1 %. A more significant improvement after heat treatment occurred in modulus of elongation with an increase by 12 %, in hardness with an increase by 12 % and the most significant improvement occurred in yield strengthwith a value of 18 %. The most significant decrease also occurred in ductility where, compared to the reference alloy, the ductility drop was by up to 67 %.