Abstract
The aim of this work was the optimizing of mechanical properties of AlSi12CuMgNi alloy  by heat treatment, as the artificial ageing with different temperatures of purpose to acquire the best mechanical properties (breaking limit and creep limit in comparison with required dilatability min. 7 – 8 %). Further aims were to search exchanges in material substructure for several heat conditions, to compare this with reached mechanical values and with influence into form and character of receiving chip on the machining under the same conditions. From heat treatment view and strength properties influence for this alloy is some important intermetallic phase Al2Cu3Ni marked as the T phase, what makes precipitates stable in higher temperatures to the 300 oC, too. Cu and Mg presence also makes intermetallic phase CuMgAl2, what participates on the strength properties increase after heat treatment. There were made chip generation experiment for every temperature regime of test. The chip generation is the best for temperature regime 140 and 180 oC / 10 hours.