Microstructural analysis of the improved creep resistance of a die-cast magnesium-aluminium-rare earth alloy by strontium additions

摘要

The microstructure of die-cast AE42 (Mg-4Al-2RE, wt.percent ) with the addition of 1 wt. percent Sr has been investigated by electron microscopy. It is shown that Sr additions result in the formation of an additional intermetallic phase with the approximate composition of Mg_8Al_4Sr. There is no evidence of the precipitation of Mg_17Al_12 phase after ageing at 200 deg for 2 weeks. The improved creep resistance of the Sr containing AE42 is associated with the reduced level of Al solute in the alpha-Mg matrix.