In aluminium alloys, Cu and Mg are added in order to increase the strength. Obtained alloys are subjected to solution treated and precipitation hardening (T6) processing. Phases are formed with simultaneous diffusions of Cu and Mg in these alloys. The purpose of this study is the modelling of elements, which are in Al-Cu, Al-Mg and Al-Cu-Mg alloys, solution treatment times into alloys both one by one and in an interrelated way and their microstructural changings. Alloys are produced by pouring to both sand and metal mould. Then, these samples are subjected to solution treated and precipitation hardening processing in different temperatures and for different periods of time. Solution treated speeds of obtained samples are examined with microstructure and image analyses through metallographic examination and a model is designed. Microhardness analyses are also made. On the other hand, residual stress of alloys are examined with hardness, DSC and microstructure analyses.