Precipitation of DO19 type metastable phase in Mg-Sn alloy

Formation of metastable precipitates in the binary Mg-Sn alloy has been investigated in the present study. The Mg-1.5 at%Sn solid solution alloy exhibits two exothermic reactions during heating up to 673 K, where lower temperature reaction with onset temperature of 364 K corresponds to the formation of metastable DO19 type precipitates, while higher temperature reaction with onset temperature of 466 K to the formation of stable Mg2Sn precipitates. The comparison of aging behavior at 423 K and 473 K indicates that lower temperature aging at 423 K results in retardation of peak aging time, but higher peak hardness due to the precipitation of DO19 type phase. (C) 2013 Elsevier B.V. All rights reserved.