Al-Mg based alloys have special attention due to the lightness of the material and certain mechanical properties and recyclability. Normally classified as non-heat-treatable these alloys obtain higher strength either by strain-hardening or by solid solution. The P/M process in the Al-Mg alloys in study leading to fine grain structure after the thermal treatment. The direct observation were made in a JEOL 200C and 2010 TEM combined with mechanical characterization utilizing Vickers microhardness measurements. The samples preparation followed the usual route of metallographic specimen preparation. The understanding of the observed phenomena depends of the fact that materials produced by powder metallurgy present complex interface reactions in a great amount of nucleation sites and a subtle change in the structure of the material causes an important variation in your properties. Alloys in study presented interesting values of properties, with evident technological potential.