Rotating water layer atomization of an aluminum-chromium alloy

In the rotating water layer atomization process, a thin stream of molten metal impinges on a rapidly spinning disk that has a roughened surface cooled by a continuous water layer. The rapid rotation of the disk disperses the water radially outward, producing a water mist in the collecting chamber, which effectively cools the metal droplets formed upon impact on the disk and thrown off tangentially. The particles obtained by this method are randomly elongated droplets, and their internal microstructure is typical of rapidly solidified material, albeit with a few peculiarities. On average, the particles are coarser but are highly convoluted, and hence the material has a microstructural refinement comparable to the finer portion of helium-atomized powders, which is of crucial importance when preparing highly alloyed, impossible-to-cast material. Mechanical testing was performed at room temperature and at 200°C and 300°C; improved mechanical properties were obtained at moderately elevated temperatures.