Floating Grains in the HDC Casting 7075 Aluminum Alloy Ingot

Abstract

7075 aluminum alloy ingot with the diameters of 100 mm was produced by Horizontal Direct-Chill (HDC). The temperature in the melt was measured and the ingots were examined in detail with the aim to reveal the floating grains in the HDC ingot. Experimental results show that very large floating grains with coarse dendrite arm spacing (DAS) mainly concentrate in the half-moon area near bottom surface of the HDC casting ingot, under the function of gravity. The floating grains in the HDC casting process is much bigger than that founded in Vertical Direct-Chill (VDC) casting process.