Assessment of exploitation properties of cast aluminium alloys on the basis of creep and LCF investigations

In spite of the great progress in modelling of material behaviour achieved during last decade, there is still a necessity to determine a model which would describe complex material processes more accurately. Among many problems to be solved, a proper model selection and its verification on the basis of experimental data seems to be the most important nowadays. Since the creep and fatigue mechanisms differ from each other, it is important to perform experiment on both kinds of mechanisms to be able to verify models. The paper presents the creep and LCF results of the AlSi8Cu3 and AlSi7MgCu0.5 cast aluminium alloys. For both materials, two levels of porosity were considered. Low porosity material (melt) was degassed during production to achieve the density index less than 3%. The high porosity material was not degassed in order to enlarge the density index up to a value higher than 6%. Up to now, many efforts are made to carry out investigations whose main objective is to find such a parameter, which would allow for describing a dam-