Effect of ball milling on structure and thermal stability of Al84Gd6Ni7Co3 glassy powders

• Ball milling affects structure and thermal stability of Al84Gd7Ni6Co3 glassy powder.
• Ball milling changes the relative amount of phases during crystallization.
• Hardness of Al84Gd7Ni6Co3 powder increases with increasing milling time.

The influence of ball milling on microstructure and thermal stability of the gas-atomized Al84Gd6Ni7Co3 glassy powder has been investigated as a function of the milling time. The results show that the traces of crystalline phases present in the as-atomized powder decrease gradually with increasing the milling time. The thermal stability of the fcc-Al primary phase increases while the thermal stability of the intermetallic phases decreases with increasing milling. Moreover, significant improvement in hardness occurs after milling, which is attributed to the amorphization of the residual crystalline phases present in the as-atomized powder. These results demonstrate that milling is an effective way for amorphizing the residual crystalline present in the amorphous matrix and to control the thermal stability of the material.