Effects of the casting temperature on microstructure and mechanical properties of the squeeze-cast Al-Zn-Mg-Cu alloy

The effects of the casting temperatures on microstructure and mechanical properties of the squeeze-cast Al-Zn-Mg-Cu alloy have been investigated in this paper. The casting temperature is selected as 660, 680, 700 and 720 degrees C, respectively. The gravity castings of the same alloy are also prepared at the above casting temperatures for comparison. Both the grain size and the dendrite arm spacing (DAS) of the squeezing casting increase with the increase of the casting temperature, as like the gravity casting. However, the casting temperature has a more obvious effect on the DAS of the gravity casting than that of the squeeze casting. The optimum casting temperatures for gravity casting and squeeze casting are 720 and 680 degrees C, respectively. However, both the gravity castings and the squeeze castings show the highest tensile elongation at the casting temperature of 660 degrees C. (C) 2010 Elsevier BM. All rights reserved.