Some aspects of solidification and homogenisation of Mg–Ag alloys

The model of non-equilibrium solidification based on assumption of full diffusion in liquid and its lack in the solid state has been adopted in Krupkowski's evaluation to Mg–Ag alloys to describe maximum microsegregation of components in the solid solution resulting in appearance of maximum amounts of non-equilibrium phases. The results were then compared with experimental in MgAg 2.5 wt.% alloys with and without addition of 0.6 wt.% zirconium and 2.5 wt% neodymium (RE) by means of scanning and transmission electron microscopy equipped with an energy dispersive spectrometer. It was found that zirconium entered the solid solution, while neodymium appeared as a net of the Mg–Ag–Nd ternary eutectic.The homogenisation process has been studied based on hardness measurements and structure analysis. The times and temperatures of homogenisation to receive uniform distribution of components in the solid solution have been chosen neglecting the remaining eutectic precipitates due to economical reasons.