Experimental investigation on microstructure and mechanical properties of direct squeeze cast Al–13%Si alloy

Squeeze casting is characterized by an applied pressure during solidification. It activates different physical processes which have metallurgical repercussions on the cast alloys. An experimental study showed the effect of the pressure levels on the microstructure and the mechanical behavior of an Al–13%Si alloy. The results showed that the applied pressure ranging from 0.1 to 100 MPa refined the microstructure, improved the tensile properties and increased the hardness Vickers in the specimen centers. Beyond 100 MPa until 150 MPa, the alloy has undergone a severe deformation in the presence of the high temperature, which generated a coarse micro-structure. Consequently, the tensile properties and the hardness decreased. The scanning electron microscopy fractographs show that the fracture mode of the squeeze cast specimens is more ductile up to 100 MPa pressure. This implies that the pressure is optimized to avoid degradation and segregation of the material during the elaboration process.