Quasi-crystalline grain-boundary phase in the magnesium die-cast alloy ZA85

The microstructures of a fine and a coarse-grained magnesium alloy with 8 wt.% Zn and 5 wt.% Al were investigated. Both microstructures consist of dendritic magnesium grains with a coarse intermetallic phase at the grain boundaries. Our investigations showed that during solidification a quasi-crystalline grain-boundary phase forms which exhibits a pronounced thermal and mechanical stability. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.