The objective of the study was to determine the feasibility of plastic forming by hot rolling of the AA2519 aluminium alloy sheets and cladding these sheets with a layer of the EN AW-1050A alloy. Numerous hot-rolling tests were carried out on the slab ingots to define the parameters of the AA2519 alloy rolling process. It has been established that rolling of the AA2519 alloy should be carried out in the temperature range of 400-440°C. Depending on the required final thickness of the sheet metal, appropriate thickness of the EN AW-1050A alloy sheet, used as a cladding layer, was selected. As a next step, structure and mechanical properties of the resulting AA2519 alloy sheets clad with EN AW-1050A alloy was examined. The thickness of the coating layer was established at 0,3÷0,5mm. studies covered alloy grain size and the core alloy-cladding material bond strength.

Studies were carried out to characterise the nickel composite coatings deposited on a 2xxx series aluminium alloy. The composite coatings were prepared in a Watts bath with the addition of fine-dispersed particles of Al 2 O 3 powder introduced in an amount of 100 g/l using current densities of 2, 4, 6 and 8 A/dm 2 . The morphology, structure, thickness and microhardness of the obtained composite coatings were described. The volume fraction of Al 2 O 3 particles in composite coating was determined. The corrosion resistance of thus produced coatings was examined. Based on the results of the conducted studies it was stated that all the produced coatings were characterised by good adhesion to the substrate, but coatings produced at high current densities were characterised by a lower content of the Al 2 O 3 reinforcing phase present in the composite.Keywords: electrodeposition, current density, composite coatings, Al 2 O 3 W pracy przedstawiono badania charakteryzujące kompozytowe powłoki niklowe osadzane na stopie aluminium serii 2xxx. Powłoki kompozytowe wytwarzano w kąpieli Wattsa z dodatkiem drobnodyspersyjnych cząstek proszku Al 2 O 3 w ilości 100 g/l przy zastosowaniu gęstości prądu: 2, 4, 6 oraz 8 A/dm 2 . Przedstawiono morfologię, strukturę, grubość oraz mikrotwardość uzyskanych powłok kompozytowych. Określono objętościowy udział cząstek Al 2 O 3 w powłoce kompozytowej. Zbadano odporność korozyjną wytworzonych powłok. Na podstawie przeprowadzonych badań stwierdzono, iż wszystkie uzyskane powłoki są dobrze przyczepne do podłoża, jednak powłoki uzyskane przy wyższych gęstościach prądów charakteryzują się niższą zawartością fazy zbrojącej Al 2 O 3 w kompozycie.

The paper presents results of the investigations on the effect of low-temperature thermomechanical treatment (LTTT) on the microstructure of AlZn6Mg0.8Zr alloy (7000 series) and its mechanical properties as well as electrochemical and stress corrosion resistance. For comparison of the LTTT effect, the alloy was subjected to conventional precipitation hardening. Comparative studies were conducted in the fields of metallographic examinations and static tensile tests. It was found that mechanical properties after the LTTT were better in comparison to after conventional heat treatment (CHT). The tested alloy after low-temperature thermomechanical treatment with increasing plastic deformation shows decreased electrochemical corrosion resistance during potentiodynamic tests. The alloy after low-temperature thermomechanical treatment with deformation degree in the range of 10 to 30% is characterized by a high resistance to stress corrosion specified by the level of PSCC indices.

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