Progress of solid-state reaction during mechanical alloying of Zr-Al-Cu-Ni bulk metallic glass-forming alloys

The progress of amorphization in mechanically alloyed Zr65Al7.5Cu17.5Ni10 powders has been investigated by X-ray diffractometry, differential scanning calorimetry, scanning and transmission electron microscopy and wavelength-dispersive X-ray spectroscopy. For this, mixtures of elemental powders were used as starting materials. Detailed investigations of the microstructural evolution during milling indicate that the amorphization proceeds by solid-state reaction, similar to what is known for mechanical alloying of binary alloy systems and other multicomponent alloys. The results are compared with interdiffusion experiments on diffusion couples of Zr-Al and Cu-Ni solid solutions isothermally annealed at elevated temperatures.