Rapidly solidified ribbons of A1 87 Ni 7 Cu 3 Nd 3 metallic glass was prepared by using melt spinning. Devitrification process of the totally amorphous ribbons was investigated by high temperature X-ray diffraction analysis, combining with differential scanning calorimetry, under continuous and isothermal heating regime. The X-ray diffraction intensity and full width at the half maximum (FWHM) were analyzed to investigate the increase of crystallized amount and growth of α-Al crystal particles. The results show that under continuous heating regime, the metallic glass devitrifies via two main stages; primary crystallization, resulting in two-phase mixture of α-Al plus residual amorphous phase, and secondary crystallization, corresponding to rapid precipitation of some inter-metallic phases in the form of dispersion or eutectic mixture. Under isothermal heating regime, only Al crystal precipitates from the Al-rich amorphous matrix at low temperature, and when heating at 280°C only Al crystal precipitates within a short time, and then Al 8 Cu 4 Nd forms, followed by Al 3 Ni, in the residual amorphous phase. When heating at higher temperature or for longer time, Al 11 Nd 3 forms, the amorphous phase disappears, and the ribbons develop into polycrystalline morphologies with multiply phase mixture of α-Al, Al 8 Cu 4 Nd, Al 3 Ni, and Al l1 Nd 3 .
|Journal||Journal of Central South University of Technology (English Edition)|
|Publication status||Published - 1 Jan 2003|
- Al-rich amorphous alloy
- Devitrification process
- Phase transformation
- Rapid solidification