The microstructure and mechanical properties of Mg-11 Li composites reinforced by the self-nascent MgO/Mg2Si particulates

The microstructure of self-nascent MgO/Mg2Si-particles-reinforced Mg-11 Li composites has been examined micrographically and confirmed through the TEM, XRD and EDAX techniques. There are two types of particles in sire. The large ones (1-5 mu m) are mainly at the grain boundary, but the smaller ones (0.2-0.6 mu m) are inside the grains. Their interfaces with matrix are very clear and a good connection would be expected; the grain size is reduced with the existence of particles. The strength of composites is much higher than that of the matrix alloy, and the ratio of YS to UTS is about 90%, which is greater than that of the matrix. The modulus is increased linearly with the increase of particles. The elongation is higher than that of the composites with Al2O3 or SiC, which may be attributed to the good interface connection.