Effect of Milling Parameters and Milling Energy on Amorphization: A Review

Amorphization via high energy ball milling is a solid state processing technique in which continuously moving balls transfer kinetic/impact energy to the powder particles. It leads to welding, fracturing, fragmentation and rewelding of the particles. During ball milling, non-equilibrium phases such as supersaturated solid solution, metastable phases, quasicrystalline phases and nanostructure alloy may form other than amorphous phase depending on energy imparted to the powder materials. It has been observed that the total energy imparted to the system plays more important role in phase transformation or amorphization than impact energy of individual balls. Mechanical alloying/milling is one of the most versatile techniques through which large amount of amorphous powders of a wide range of compositions can be synthesized. Experimental results indicated that instead of individual parameter, total energy should be taken into consideration during amorphization. The current authors have also observed that the total energy plays an important role in amorphization of Al 86 Ni 8 Y 6 glassy system.