The Study on Microstructures and Properties of the Direct Squeeze Casting Al-Zn-Mg-Cu-Zr-Sc Alloy

Abstract

Trace elements Sc was added to the Al-Zn-Mg-Cu-Zr alloys, the differences of the microstructure and properties using gravity casting and squeeze casting are compared. The result shows that through the addition of trace elements Sc, the Al-Zn-Mg-Cu-Zr alloys casting microstructure was refined effectively, dendrite segregation was alleviated and the mechanical property of alloy was enhanced. Using squeeze casting forming could improve the compactness of the alloys, decrease the probability of occurrence of shrinkage cavities, porosity and segregation, in addition, the grain could be refined by the pressure forced on the alloy melt. Combined the element Sc microalloying and squeeze casting used in Al-Zn-Mg-Cu-Zr alloy forming, we could get the casting with uniform, compact, little defect microstructures. This combination could provide a new way to the Al-Zn-Mg-Cu-Zr alloy forming.