What process produces irregularly shaped, tough metal powders that have a relatively high impurity and surface-oxygen content?

The process that produces irregularly shaped, tough metal powders characterized by relatively high impurity and surface-oxygen content is water atomization. This technique involves transforming molten metal into powder by dispersing it in a water jet. During this process, the water rapidly cools the molten metal, resulting in the formation of irregularly shaped particles.

The cooling rate in water atomization is typically slower compared to gas atomization, contributing to the production of tougher, yet less pure, metal powders due to the potential for oxidation and contamination from the water medium. The interaction with water can lead to higher levels of oxygen and other impurities being retained in the powder, as the water can introduce these elements into the powder during the cooling process. This is distinct from other methods like gas atomization, which generally produces more spherical and purer powders due to the inert gas environment which limits oxidation and contamination.