Variability of skin thickness in an AM60B magnesium alloy die-casting

The skin thickness is investigated in regions of different solidification conditions in a die-cast AM60B magnesium alloy component. The results of several different techniques for determining the skin thickness in six different samples are compared. The hardness profile, the elemental aluminum and oxygen contents, the change in grain sizes, the change in eutectic percentage, and the onset of large α-Mg dendrites through the casting thickness are used to determine a skin thickness. These different criteria for determining the skin thickness yield equivalent results. Regions of different solidification conditions result in different skin thickness measurements. The flow stress near the yield point is found to correlate well with the observed skin fractions determined from this study.