Mechanically alloyed Zr–Cu–Al–Ni–C glassy powders

In this contribution we report on the synthesis of glassy Zr55Cu30Al10Ni5 alloys with a carbon content up to 4 at.% by mechanical alloying which cannot be produced by casting techniques. X-ray analysis and differential scanning calorimetry, both in isochronal and isothermal mode, were carried out to assess the glassy nature of the powders. The viscosity was investigated by parallel plate rheometry and the crystallisation mechanism and kinetics are discussed in the framework of the Johnson–Mehl–Avrami (JMA) model. The comparison between carbon-free and carbon-containing alloys suggests a strong influence of increasing carbon content on the total free volume and viscous flow behaviour of the alloys and on the chemical and topological short-range order, affecting significantly the thermal stability and the crystallisation behaviour of the glassy phase and the supercooled liquid.