Effects of Zr element and Solidification Parameters on the microstructure and tensile properties of Al-7%Si-0.5%Mg Alloy

In this investigation, experiments were carried out to study the relationship of master alloy Al–5Zr and solidification parameters in Al-7wt%Si-0.5wt%Mg casting with various thicknesses under the same solidification condition. The optimum level of Zr as Al–5Zr grain refiner was found to be ( 0.03 wt.%), respectively. It was found that 0.03 wt% Zr addition could refine the microstructure significantly and modify the eutectic Si from plate-like morphology to fiber converted. The results show that the Increasing cooling rate through reduced sections, decreases grain size and dendrite arm spacing ,but Zr-refined specimens showed lowest sensitivity to cooling rate. The relationships between the microstructre and cooling rate have investigated. The microstructural characterization was carried out by optical microscopy and image analysis. meachanical properties also have investigated at various thicknesses.

کلیدواژه ها:

Aluminium alloys ، Casting ، grain refiner