EARLY STAGES IN THE AGING OF ALLOYS IN THE AL-MG AND AL-MG-ZN SYSTEMS

High mechanical properties and good corrosion resistance are achieved in the Al-Mg system after quenching. It is here that problems arise due to difficulties in maintaining a stable structure, and the above characteristics, during long-term natural aging. The alloying of aluminum-magnesium alloys with zinc leads to a qualitative change in the phase composition and to a change in the nature of the dispersion hardening. At a definite ratio of magnesium and zinc in the alloy one can obtain higher (in comparison with alloys from the Al-Mg system) mechanical properties without a loss in the corrosion resistance after thermal treatment (quenching + artificial aging). In this study the decomposition kinetics (especially in the initial stages) of the solid solution in Al-Mg and Al-Mg-Zn systems is examined.