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By using the wrought aluminum alloys can be created castings with higher mechanical properties than the castings made of standard foundry aluminum alloys, but it is necessary to handle the process of making sound castings without any defects such as hot tears and shrinkage porosity. In experiments, we have been studied of wrought aluminum alloy EN AW-2024 which has been processed by the casting with crystallization under pressure with forced flow. Castings were heat treated by standard T6 heat treatment.KEYWORDS: wrought aluminum alloy, EN AW-2024, casting with crystallization under pressure, mechanical properties IntroductionAlthough aluminum alloys do not belong to the latest breakthrough materials [1], they are currently at the top in terms of their use in worldwide practice. Castings made of foundry aluminum alloys has probably reached its top in terms of mechanical properties and probably neither on-coming casting technology does not produce castings with higher mechanical properties. Therefore, in order to take advantage of casting technology in comparison with forming technology, for example higher shape complexity of the products, came a time of examination of wrought aluminum alloys usability in the production of castings. It has been already engaged of all unconventional technologies to the research such as casting with crystallization pressure (direct and indirect) [2,3] or semi-solid metals casting [4][5][6]. Investigated are the alloys of 2xxx, 6xxx and 7xxx series because they offer the highest mechanical properties [7,8]. One of the difficulties in casting of these alloys is a wide solidification range that cause higher tendency to the formation of defects during solidification, for example shrinkage porosity and hot tears [9,10]. The aim of this research is to investigate the effects of casting parameters (pouring temperature and die temperature) in the casting with crystallization under pressure with forced flow [11] on the mechanical properties and microstructure of castings made of wrought aluminum alloy EN AW-2024 in the as-cast state and after heat treatment. Material and methodsExperimental material was prepared using four different ways of casting with crystallization under pressure with forced flow (Tab. 1). Castings were cup-shaped ( Fig. 1) with a height of approximately 130 mm, a wall thickness of 15 mm and bottom thickness of about 20 mm (depending on the height of casting).

Utilization of Heat Treatment Aimed to Spheroidization of Eutectic Silicon for Silumin Castings Produced by Squeeze Casting This paper describes the possibility of using very short periods of solution annealing in the heat treatment of unmodified hypoeutectic silumin alloy AlSi7Mg0,3 casted by method of casting with crystallization under pressure with forced convection (direct squeeze casting process). Castings prepared at different casting parameters were subjected to special heat treatment called SST (Silicon Spheroidization Treatment), which were originally used only for the modified silumin alloys to spheroidization of eutectic silicon. Temperature holding time in solution annealing of T6 heat treatment is limited in the SST process to only a few minutes. It was studied the effect of casting parameters and periods of solution annealing on ultimate strength, yield strength, and especially ductility that in the unmodified silumin alloy castings is relatively low.

Requirement on the minimum value of elongation for critical components is about 15 %. The research deals with the possibility of replacing the dendritic morphology of primary solid solution and brittle eutectic silicon plates with finer particles with a more suitable morphology and size, and the possibility of increasing the mechanical properties. Introduced first part is focused on the process of preparation of experimental material and mechanical properties.