Exploration of the viscosity temperature dependences and microstructure of magnesium-based commercial alloy AZ91D with small additions of calcium

Abstract

The technique of rotating oscillation damping of a crucible filled in with the melt under investigation was used for measurement of viscosity of the Mg-based AZ91D commercial alloy with various additions of calcium. The viscosity was measured in liquid state in temperature interval from 600 up to 840 degrees C. The comparative metallographic investigation of the structure of samples with calcium content of 0.0, 0.4, 0.6 and 0.8 wt.% which were crystallized just after re-melting at the temperature of 640 degrees C and after heating in liquid state up to 850 degrees C were made. It was shown that the thermal treatment of samples in liquid state is accompanied by considerable changes in the cast structure that forms after the crystallization of the samples.