Structural evolution during crystallization in phase separated Ti-Y-Al-Co metallic glass

Structural evolution during heat treatment of melt spun Ti36Y20Al24Co20 alloy was studied using differential scanning calorimetry, X-ray diffractometry and transmission electron microscopy. The as-melt spun Ti36Y20Al24Co20 specimen showed a hierarchical complex microstructure consisting of Ti-rich and Y-rich amorphous phases and crystallized with two-step process. Crystallization in the phase separated two phase mixture took place in a confined mode due to different thermal stability and complex microstructure, resulting in various nano-scaled microstructural formation ranging from fine distribution of crystalline particles in amorphous matrix to fine distribution of amorphous particles in crystalline matrix.