PROCESS FOR OBTAINING ALUMINIUM ALLOYS WITH IMPROVED MECHANICAL CHARACTERISTICS

The invention relates to a process for obtaining deformable foundry aluminium alloys with mechanical characteristics improved by treating the metal bath with nanostructured prealloys of the AlSr10 and AlTiB1 type. According to the invention, the process consists in treating the metal bath with products as compressed briquettes made of nanostructured strips obtained by an ultra-fast melt spinning solidification process, whose parameters are the melting-maintaining temperature of 1100...1300°C, the distance of 1.5 mm between the crucible and disk, the angle of 70° made by the disk with the crucible and the diameter of 1 mm of the crucible orifice, the foundry alloy 357.0 being micro-alloyed with nanostructured prealloys of AlSr10 and AlTi5B1 in a mass percentage < 0.3% AlSr10 and < 5% AlTi5B1, respectively, with the time of maintaining in the batch < 5 minutes, with a generation of a modification index 6, with the grain size < 80 μ m and with improved mechanical characteristics: mechanical resistance higher by 20%, hardness higher by 10% and relative elongation higher by 10% in relation to the alloys treated by classic procedures, and the aluminium alloy 5083 is micro-alloyed with a nanostructured prealloy AlTi5B1 in a mass percentage < 0.7% AlTi5B1, with a time of maintaining in the batch < 5 minutes, producing a grain size < 60 μ m and having the same improved mechanical characteristics as those of the micro-alloyed foundry alloy.