| Devitrified amorphous alloy nanocomposites with nanoscale precipitates are regarded as new prospective structural materials with superior mechanical properties such as high strength and high shear resistance. Several different models for the strengthening mechanism in partially devitrified amorphous nanocomposite materials have been proposed; shear resistance model, matrix solute enrichment model and phase mixture model. However, the strengthening mechanism of the devitrified amorphous nanocomposites has not been clearly elucidated. In order to analyse the hardening behaviour of the partially devitrified amorphous alloys, the change in solute concentration of Zr-based alloys during the devitrification process by heat treatment was investigated. It was found that the solute concentration of the remaining amorphous matrix increases during the devitrification when the solute concentration of the initial amorphous alloy is higher than that of the precipitate. On the other hand, the solute is diluted in the remaining amorphous matrix during the devitrification when the solute concentration of the initial amorphous alloy is lower than that of the precipitate. Investigating this solute concentration change and the associated mechanical properties shows that it is the phase mixtures model, and not the solute concentration model, that provides an adequate description of the devitrified amorphous nanocomposites. |
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