Thermal stability and crystallization kinetics of mechanically alloyed TiC/Ti-based metallic glass matrix composite

A Ti-based metallic glass matrix composite with 10 vol % TiC is synthesized by mechanical alloying. The thermal stability and crystallization kinetics of the metallic glass and composite powders are investigated by differential scanning calorimetry in the mode of isochronal heating and isothermal annealing. The isothermal transformation kinetics is analyzed by the Kolmogorov-Johnson-Mehl-Avrami equation. The values of the Avrami exponent calculated for low crystallization volume fractions imply that the crystallization of both types of powders is governed by diffusion-controlled three-dimensional growth. The mean activation energy of crystallization for the composite is slightly lower than that of the Ti-based metallic glass. The addition of 10 vol % TiC particles into a Ti-based metallic glass matrix may slightly affect the crystallization kinetics of the glassy matrix. (c) 2006 American Institute of Physics.