Rapid Mechanical Alloying for Metal Powder Production

An important area of research in the field of powder metallurgy (PM) is the production of alloyed metal powders. Most alloyed metal powders are produced by rapid solidification or milling techniques. Typical problems encountered are compositional control and volume of production, which lead to high costs. Mechanical alloying (MA) is a milling technique that has the capability of producing non-equilibrium powder compositions, without many of the difficulties of rapid solidification processes. However, like most milling processes, MA typically suffers from low production volumes and long milling times. A method for producing sizable volumes of powders in times typically less than an hour has been developed. A ring grinder and a saucer mill have been used to demonstrate the efficiency of this procedure. Powders of several brittle stoichiometric intermetallic compounds have been produced by this method. In addition, this technique has been used to produce metal powders by reducing bulk pieces of existing ductile alloys. MA powders typically are not exposed to high temperatures. Therefore, problems with reactivity and the loss of volatile elements such as occur during high temperature processing can be avoided