Effect of Alloying Elements on the Strength and Casting Characteristics of High Strength Al-Zn-Mg-Cu Alloys
Small amounts of various alloying elements were added to a high strength Al-Zn-Mg-Cu alloy and their effects on the microstructure, mechanical properties, and casting characteristics were investigated. Silicon additions with or without extra Mg to the Al-Zn-Mg-Cu alloy could enhance the castability such as fluidity, feedability, and hot tearing resistance significantly while maintaining a high strength. However, in these alloys containing silicon the compositional adjustment was necessary to prevent the Mg2Si phase formation from degrading the precipitation of MgZn2 phase that is responsible for the high strength. Zr addition to the base alloy was also observed to improve the feedability without deteriorating the tensile strength.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
K. T. Kim et al., "Effect of Alloying Elements on the Strength and Casting Characteristics of High Strength Al-Zn-Mg-Cu Alloys", Materials Science Forum, Vols. 475-479, pp. 2539-2542, 2005