Preparation and thermal stability of mechanically alloyed amorphous Ni-Zr-Ti-Si composites

The feasibility of preparing amorphous Ni57Zr20Ti20Si3 composite powders by mechanical alloying of pure Ni, Zr, Ti, Si, and ceramic powder mixture after 5h milling was investigated. The as-milled powders were examined by X-ray diffraction, scanning electron microscopy, and differential thermal analysis. Amorphous Ni57Zr20Ti20Si3 composite powders were prepared successfully at the end of milling for all the compositions studied. The thermal stability of the amorphous matrix is not significantly affected by the presence of the ceramic particles. It is suggested a partial dissolution of the atoms constituting the ceramic species in the amorphous phase can result change of matrix composition and lead to the variation of the glass transition and crystallization behaviors.