The effect of nitride addition on the thermal stability of mechanically alloyed amorphous Zr65Al7.5CU17.5Ni10 alloy

The elemental powder mixtures with a composition of Zr65Al7.5Cu17.5Ni10 together with 10 vol.% UN, TiN and Si3N4 particles were mechanically alloyed to form the nitride/metallic glass composite. The effect of the added nitride particles on the thermal stability was analyzed using X-ray diffraction, transmission electron microscopy and differential scanning calorimetry (DSC). Milled to a steady state, initial particles of the nitride crystallite were refined to nano-scare and homogeneously dispersed in the amorphous Zr-based alloy matrix. Compared with the Zr-based metallic glass without nitride, the nitride-containing composites exhibit a similar large supercooled liquid region and the crystallization activation energy. At a heating rate of 40 K/min, there is no appreciable change in the glass transition temperature, but the onset temperature of the primary crystallization increases by about 10K. The nitride addition results in an extension about 10 K for the temperature interval (Delta T-x) between the T-g and the T-x.