Microstructure and mechanical properties of Mg-2.5Si-xCe in-situ particle reinforced composites prepared by rapid solidification process

Abstract

In this study, Mg-2.5Si-xCe alloys with different Ce contents were fabricated by a rapid solidification process. Two different in-situ phases, namely coarse primary Mg2Si with a size of ∼10 μm and tiny CeMg2Si2 with a size <400 nm, were formed and well dispersed in the composite matrix. Nanosized CeMg2Si2 phases can act as excellent reinforcements when the appropriate ratio of Si and Ce elements was preset. The compressive test results showed that the strength of the samples (Mg-2.5Si-xCe) become stronger with increasing Ce content. The enhancement of the composite mechanical properties was attributed to the reduction of Mg2Si phases and the dispersion strengthening of the nanosized CeMg2Si2 phases.