Crystallization of amorphous Cu50Ti50 alloy prepared by high-energy ball milling

Amorphous Cu50Ti50 alloy was prepared by short-term (20 min) high-energy ball milling (HEBM). According to TEM, electron diffraction, and HAADF STEM results, the material was 93% amorphous with an admixture of nanocrystalline particles 2-8 nm in their size. Thermal stability and crystallization of amorphous Cu50Ti50 was studied by differential scanning calorimetry (DSC) and time-resolved XRD (TRXRD). Depending on heating rate, the crystallization of Cu50Ti50 took place within the temperature range 298-397 °C. The activation energy (199 ± 4 kJ/mol) was found by using the Kissinger equation. Time-resolved diffraction patterns have revealed that the phase transition proceeds without melting within a time period of 20-30 s and the onset of crystallization gets started around 300 °C which is markedly lower than the melting temperature in the Cu-Ti system (982 °C). Based on our TRXRD results, a mechanism of the phase transition under study was suggested.