The microstructures of a fine and a coarse-grained magnesium alloy with 8 w
t.% Zn and 5 wt.% Al were investigated. Both microstructures consist of den
dritic magnesium grains with a coarse intermetallic phase at the grain boun
daries. Our investigations showed that during solidification a quasi-crysta
lline grain-boundary phase forms which exhibits a pronounced thermal and me
chanical stability. (C) 2001 Acta Materialia Inc. Published by Elsevier Sci
ence Ltd. All rights reserved.