Nanocrystallization of bulk Zr-Cu-Ti metallic glass

The phase transformations during heating of Zr30Cu60T10 bulk metallic glass were studied by differential scanning calorimetry, dilatometry, X-ray diffraction, transmission and high resolution electron microscopy. The crystallization of bulk metallic glass was found to occur in several stages. According to X-ray diffraction studies the structure was closely similar to amorphous structure when the sample was heated to the end of the first DSC sub-peak (781 K). However, the volume effect of the first stage of transformation is 1.6%; it forms about 80% of total volume effect of the crystallization (2%). A change of the shape of the diffraction maxima has been analyzed for the cases of structure relaxation and nanocrystalline structure formation. The nanocrystalline structure with very fine,grain size was found to form during first stage of crystallization. The grain size of the nanocrystals was 1-5 nm. (C) 2001 Elsevier Science B.V. All rights reserved.