Vliv stupně naplynění a rychlosti ochlazování na porezitu Al - slitin

The principle of this experiment was in an analysis of the influence of the Density Index and different cooling rate on the porosity according to metallurgical changes of molten metal (gassing, degassing). Simple castings made from AlSi9Cu3 alloy were poured into permanent mould and sand moulds to getting a different cooling rates. Porosity was measured on the microstructure of each sample. Significant values were shape factor, size and distribution of the bubbles. The mechanical properties such as tensile strength (Rm) and yield strength (RP0,2) were measured on these samples. The tensile strength is seriously decreased as the hydrogen concentration increases. The yield strength is only very slightly affected.