Thixomolded* magnesium alloy AM60 plates joined by friction-stir welding were observed to be as strong or stronger than the unwelded base material. The thixotropic microstructures of the as-molded plates consisted of either 3% or 18% primary solid fraction of alpha-Mg globules (similar to45 mum average size) in a eutectic mixture consisting of alpha-Mg grains (similar to10 mum) surrounded by Mg17Al12 intermetallic grains in the alpha-Mg grain boundaries (having an average size of 1-2 mum). This complex, composite microstructure became a homogeneous (Mg + 6% Al)), recrystallized, equiaxed grain (10-15 mum) microstructure in the weld zone. (C) 2003 Kluwer Academic Publishers.