The polished sections for microstructural observations were prepared using SiC paper up to a grit number of 1200,polished using first an Al2O3 slurry and then colloidal silica. Themicrostructure was observed in the unetched condition using a light opticalmicroscope(OM)and a scanning electronmicroscope(SEM), coupled with energy-dispersive X-ray spectroscopy(EDS).