Currently there is a constant development in the field of aluminium alloys engineering. This results from, i.a., better understanding of the

mechanisms that direct strengthening of these alloys and the role of microalloying. Now it is microalloying in aluminum alloys that is

receiving a lot of attention. It affects substantially the macro- and microstructure and kinetics of phase transformation influencing the

properties during production and its exploitation. 7xxx series aluminum alloys, based on the Al-Zn-Mg-Cu system, are high-strength

alloys, moreover, the presence of Zr and Sr further increases their strength and improves resistance to cracking.

This study aims to present the changes of the properties, depending on the alloy chemical composition and the macro- and microstructure.

Therefore, the characteristics in the field of hardness, tensile strength, yield strength and elongation are shown on selected examples.

Observations were made on ingot samples obtained by semi-continuous casting, in the homogenized state.

Samples were prepared from aluminum alloys in accordance with PN-EN 573-3: 2013. The advantage of Al-Zn-Mg-Cu alloys are

undoubtedly good strength, Light-weight and resistance to corrosion. As widening of the already published studies it is sought to

demonstrate the repeatability of the physical parameters in the whole volume of the sample.