The paper deals with the impact of technological parameters on the mechanical properties and microstructure in AlSi12 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 and 150 MPa. From the experiments we

can conclude that operating pressure of 100 MPa is sufficient to influence the structural characteristics of the alloy AlSi12.

The change in cooling rate influences the morphology of the silicon particles and intermetallic phases. A change of excluded

needles to a rod-shaped geometries with significantly shorter length occurs when used gravity casting method. At a pressure

of 100 MPa was increased of tensile strength on average of 20%. At a pressure of 150 MPa was increased of tensile strength

on average of 30%. During the experiment it was also observed, that increasing difference between the casting temperature

and the mold temperature leads to increase of mechanical properties.

The paper deals with the impact of technological parameters on the heat transfer coefficient and microstructure in AlSi12 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 and 150 MPa. The pressure applied to the melt causes a significant increase of

the coefficient of heat transfer between the melt and the mold. There is an increase in heat flow by approximately 50% and the heat

transfer coefficient of up to 100-fold, depending on the casting conditions. The change in cooling rate influences the morphology of the

silicon particles and intermetallic phases. A change of excluded needles to a rod-shaped geometry with significantly shorter length occurs

when used gravity casting method. By using the pressure of 150 MPa during the crystallization process, in the structure can be observed an

irregular silica particles, but the size does not exceed 25 microns.

The paper deals with squeeze casting technology. For this research a direct squeeze casting method has been chosen. The influence of process parameters variation (casting temperature, mold temperature, pressure) on mechanical properties and structure will be observed. The thicknesses of the individual walls were selected based on the use of preferred numbers and series of preferred numbers (STN ISO 17) with the sequence of 3.15, 4.00, 5.00, 6.00 and 8.00 mm. The width of each wall was 22 mm with a length of 100 mm. As an experimental material was chosen the AlSi12 and AlSi7Mg0.3 alloys. The mechanical properties (UTS, E) for individual casting parameters and their individual areas of different thicknesses were evaluated. In the structure the influence of pressure on the change of the eutectic morphology, the change of the volume of eutectic and the primary alpha phase, the effect of the pressure on the more fine-grain and the regularization of the structure were evaluated.