Effects of grain size and dendrite cell size on aging characteristics of rapidly solidified Al-Zn-Mg alloy

Abstract

Al-4.2%Zn-1.2%Mg alloy was rapidly solidified in a water-cooled copper mold. Hardness measurements, X-ray small angle scattering method and microscopy were applied. Aging characteristics of the Al-Zn-Mg alloy rapidly solidified depend on the dendrite cell size, but do not on the grain size. The agehardenability is moderated as the dendrite cell size increases. This fact is attributed to the decrease of solute concentrations in the dendrite cell matrix in accordance with the increase in the dendrite cell size.