Research Project; Contract No.: 4731/B/T02/2008/34

The aim of the project was to characterize the intermetallic phases Al-Mg-Si-Cu and Al-Fe-Si-Mn found in industrial aluminum alloys 2xxx and 6xxx series after casting and after heat treatment - homogenization - depending on the cooling speed and the ratio of elements present in the material alloy. A qualitative analysis of intermetallic phases was performed in terms of morphology, chemical composition (SEM + EDXS) and crystallographic structure identified by the EBSD method. XRD and DSC were also used to fully characterize the phase.

The tests were carried out on the alloy of the 2xxx series and on the alloy of the 6xxx series - samples cast in laboratory conditions and on industrial ingots

The base of alloys in the 2xxx series was 2014. In laboratory cast alloys, silicon and magnesium content was determined in the range of extreme norm values, so that the Mg / Si ratio was 0.2, 0.4, 0.9 and 1.6, respectively. The content of copper and iron was at the highest according to level standards, i.e. around 5% Cu and 0.4% Fe. (8 variants at two cooling speeds)

The base of alloys in the 6xxx series was 6061A. Similar to the 2xxx series alloys, the silicon and magnesium content was determined in the range of extreme values. The Mg / Si ratio was 1, 1.5, 2 and 3, respectively. The content of copper and iron was similarly highest, according to standards, level and was - Cu = 0.6% by weight, and Fe-0.5% by weight (8 variants at two cooling speeds).

Such determination of the chemical compositions of alloys allowed for the formation in 2014A and 6061A alloys respectively of different intermetallic phases possible to occur in industrially cast ingots for plastic working.

As a comparative material, from the current production of GK "Kęty", material was obtained in the form of ingot templates F 230mm from alloys 2014A and 6061A with similar chemical compositions to those assumed and cast in laboratory conditions. In ingots with this diameter, the cooling speed varied from about 5 to 20 K / sec. It was therefore possible to check whether the chemical composition and morphology of intermetallic phases occurring in the material cast in industrial conditions were comparable to those formed in alloys with similar chemical composition and cast in laboratory conditions.

The total cost of the project: 250 000PLN