Effects of manganese on the microstructure and dynamic precipitation in creep-resistant cast Mg-Ce-Mn alloys

Abstract

The creep-strengthening effect of Mn in Mg-Ce alloys has been studied via creep testing and transmission electron microscopy. It appears that alpha-Mn precipitates may serve as nucleants for the intradendritic heterogeneous nucleation of Mg12Ce precipitates which play a primary role in creep strengthening. The nucleation caused a decrease in the maximum size and a change in the morphology of Mg12Ce precipitates. It was observed that the nucleation and growth of alpha-Mn and Mg12Ce precipitates are mutually affected by the presence of the other. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.