Study of mechanical milling mechanisms in Al-Si eutectic system

Mechanical milling process is a well-known technique used widely to synthesize nanocrystalline materials. Determining optimal milling parameters in order to improve milling process efficiency and quality of the produced nanoparticles, is indispensable. In this study, eutectic Al-Si mixture was mechanically alloyed in a planetary fast mill in different milling conditions (5, 15, 30, 45 and 60 h) in argon atmosphere with a ball to powder weight ratio of 10:1. The effect of milling time was investigated by X-ray diffraction and scanning electron microscope. Not only, increasing milling time lead to a reduction in crystallite size with a transition region as the Si diffused in the Al lattice at optimum milling time (45 h), but also it changed slightly the morphology of mixed powders from lamella to globular shape.