Temperature rise during mechanical alloying

Mechanical alloying has been well developed to the level of industrial application for manufacturing a wide range of materials, including ODS alloys (1-3), intermetallics (4,5), sold solution alloys (6,7) and amorphous materials (8,9). In spite of this progress, research efforts to understand the basic operating mechanisms during the process of mechanical alloying have been very limited. Understanding the heat dissipation during alloying is one of them. It is very likely that the temperature rise of the powder compact caused by the impacting grinding media could play a central role in most of these operating mechanisms, particularly for diffusion to take place during alloying. However, the efforts (8, 10-11) to describe the heating effects during MA arc often based on assumptions related to bulk impacted material and therefore, may not represent the true maximum temperature at the areas close to impact. This note is an attempt to provide calculations for the temperature rise from different paints of view, which seem to indicate that indeed in the mechanical alloying process, a significant increase in localized temperature is a likely event.