Effect of Squeeze Casting on Microhardness and Microstructure of Al-3Cu-xSi Alloy

Aluminum alloys of the ANSI series 319 present Si and Cu as the main alloying elements and the mechanical strength of these alloys can be improved by the precipitation of the metastable Al2Cu phase. Squeeze Casting is a casting process in which the cast metal is deposited in a metal mold and solidified under certain pressure exerted by a punch. This process provides changes in the microstructure which lead to changes in the mechanical properties of the material such as the increase in the microhardness of the processed alloy. alloys Al-5,5% Si-3% Cu, Al-7,5% Si-3% and Al-9% Si-3% Cu alloys were solidified by the squeeze casting process to analyze the microstructural and microhardness variations. Pressures of 0 MPa, 50 MPa, 100 MPa and 150 Mpa were used. In general, with increasing pressure and composition, the λ2 values decrease from the metal/mold interface, especially at pressures of 150 MPa and Composition of 9%Si, on the other hand the increase of these variables leads to the formation of more phases Al2Cu metastable that have a decrease in the Microhardness of the material, in addition to the formation of other phases due to the proximity to the eutetic.