Milling of materials, whether hard and brittle or soft and ductile, is of prime interest and of economic importance to the powder metallurgy (PM) industry. This article discusses the principles of milling, milling parameters, and the powder characteristics required for the process. It discusses the changes in powder particle morphology that occur during milling of metal powders produced by various processes such as microforging, fracturing, agglomeration, and deagglomeration. The article also provides useful information on milling equipment such as tumbler ball mills, vibratory ball mills, attrition mills, and hammer and rod mills.

This article focuses on the significant fundamental powder characteristics, which include particle size, particle size distribution, particle shape, and powder purity, followed by an overview of general and individual powder production processes such as mechanical, chemical, electrochemical, atomizing, oxide reduction, and thermal decomposition processes. It also covers the consolidation of powders by pressing and sintering, as well as by high density methods. Further emphasis is provided on the distinguishing features of powders, their manufacturing processes, compacting processes, and consolidated part properties. In addition, a glossary of powder metallurgy terms is included.