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This paperwork is focused on the quality of AlSi6Cu4 casting with different wall thicknesses cast into the metal mold. Investigated are structural changes (the morphology, size, and distribution of structural components). The quantitative analysis is used to numerically evaluate the size and area fraction of structural parameters (α-phase, eutectic Si, intermetallic phases) between delivered experimental material and cast with different wall thicknesses. Additionally, the Brinell hardness is performed to obtain the mechanical property benefits of the thin-walled alloys. This research leads to the conclusion, that the AlSi6Cu4 alloy from metal mold has finer structural components, especially in small wall thicknesses, and thus has better mechanical properties (Brinell hardness). These secondary Al-castings have a high potential for use in the automotive industry, due to the thin thicknesses and thus lightweight of the construction.

This paper will investigate the changes in size and amount of the microstructural features in secondary aluminium casts associated with different wall thickness. The experimental samples were casting into the sand mould. The changes were documented and assessment by using optical microscope and methods of quantitative analysis. The results shows that increasing wall thicknes lead to formation larger second phases and coarsening of the matrix, which lead to decreasing mechanical properties.

The article deals with the effect of variaton of the technological parameters on the change mechanical properties and density of the AlSi7Mg0.3 alloy using squeeze casting technology. The AlSi7Mg0.3 alloy has been chosen because the acting pressure has the most significant impact on Al-Si alloys. For the make a samples was used a direct squeeze casting technology. Differently casting temperatures and mold temperatures at the acting pressure of 30 MPa were varied for individual samples. From the mechanical properties was specifically evaluated tensile strength and elongation.

The paper deals with the methodology of heat transfer coefficient measuring while using squeeze casting process. The casting with crystallization under pressure was used, specifically direct squeeze casting method. The pressure applied to the melt causes a significant increase (up to ten times) of the coefficient of heat transfer between the casting and the mold. The paper deals also with obtained results of the measured temperatures in the mold and the casting. The goal was to affect crystallization by pressure with value 100 MPa. On the basis of the measured variables were calculated values of heat flux between casting/mold, and consequently also the values of heat transfer coefficient.

Estimation of the heat flow at the metal-mold interface is necessary for accurate simulation of the solidification processes. For the numerical simulation, a precise prediction of boundary conditions is required to determine the temperature distribution during solidification, porosity nucleation, microstructure development, and residual stresses. Determination of the heat transfer coefficients at the metal-mold interface is a critical aspect for simulation of the solidification process and the microstructure modeling of the castings. For crystallization under the pressure and for thin-walled castings, HTC evaluation is important due to the very limited freezing time.

Submitted article deals with the methods to improve mould breathability when using the Patternless process method and also examines the influence of opening material grain size on the dimensional and shape precision of made castings. Mentioned methods are based on the principle of direct milling cavity into block from moulding mixture with CNC machining. As the moulding material was used CT moulding compound composed of opening materials SH 35, SH 31 and water glass as binder. The curing process took place by purging CO2 gas through moulding compound. To achieve the highest quality surface cavity was used protective coating PROTECT WC1. The final shape and dimensional accuracy of the castings was evaluated using a 3D measuring device and a contourgraph.

The paper deals with the impact of technological parameters on the heat transfer coefficient and microstructure in AlCu4Ti alloy using squeeze casting technology. The casting with crystallization under pressure was used, specifically direct squeeze casting method. The goal was to affect crystallization by pressure with a value 100 MPa. The pressure applied to the melt causes a significant increase of the coefficient of heat transfer between the melt and the mold. By rapid cooling the casting was reflected by changes in the structure. On the basis of the measured values of heat flux and heat transfer coefficient were calculated at the interface between the cast and the mold. The observation of microstructure can conclude, there is no significant influencing of the primary phase. As a result of the pressure was reduced porosity.

This study investigated the effects of squeeze parameters on the properties of squeeze castings and the optimum parameters for producing squeeze castings from Al-Si alloy. It also compared the properties of the squeeze castings with those of chill castings. Squeeze castings were made from AlSi7Mg0.3 alloy using pressures of 15-22.5-30MPa with the alloy poured at 680, 700, 720 and 740°C into a die preheated to 150, 200 and 250°C. Squeeze time was 10s. At the pressure effect during crystallization there is possible to observe the refinement of eutectic silicium with the increasing pressured. Eutectic Si is excreted in clusters in comparison with non-influenced structure. There comes to increasing of failure strength and mainly of elongation. The hardness of investigated samples was not changed markedly. At the pressure of 15 MPa there comes to inadequate pressure influence, what causes the creation of shrinkage in the longitudinal part of the sample. This decreases the mechanical properties.

This article deals with the influence of different specific pressures on the heat flux from the casting into the mould. The determination of the heat flux at different crystallization conditions will be the basis for the simulation calculation of the solidification with the crystallization under pressure.The article presents the results of the measured temperatures inside of the mold and casting by influencing of the crystallization pressure of 100 MPa. For comparison, results are also presented in gravity cast specimens. Also are presented pictures of microstructure that were observed near the surface of the casting. On the basis of the measured temperatures inside of the mold are calculated as a value of the heat flow from casting into the casting mold. The results of heat flow correspond with the evaluation result of the microstructure.