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High temperature homogenization annealing of DC cast billets from aluminium alloys used for extrusion pressing is considered as one of substantial technological operations during extrusion processing. The structure of DC cast billets consists of dendrite cell structure and contains coarse and inhomogeneously distributed intermetallic phases of β-AlFeSi and α-Al(Fe,Mn)Si type.Structure after a homogenization annealing is quite decisive for both the final properties of extrusions and the extrudability of the cast structure. The present paper deals with the medium strength heat-treatable EN AW-6082 alloy. It is investigated the effect of heating rate, time at the annealing temperature and the cooling rate of continually cast billets during the homogenization annealing on the changes of electrical conductivity, structure and intermetallic phases.

The manufacture of die forgings from Al-Mg-Si type alloys is one of important topics of material and forming technology development. One of innovation factors affecting the forging technology is based on the use of continually cast rods instead of extruded ones. This change of technology is, however, connected with some problems concerning the structure, an inhomogeneous surface layer, surface morphology of cast rods and increased flow stress of the cast structure as well. The present paper deals with some aspects relating to the inhomogeneity of structure, intermetallic phases and thermomechanical treatment. The investigation of the cast and extruded structure was carried out with the help of optical and electron microscopy.

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BaTiO