Machinability of Powder Metallurgy Steels
Machinability is more important in extending the applications of powder metallurgy (PM). This article provides an overview of the machining process and machinability measurement of PM steels. It discusses various approaches to improve machinability, including the closure of porosity, green machining, presintering, microcleanliness improvement, free-machining additives, microstructure modification, and improvements in tool materials. The effects of free-machining agents on machinability and the sintered properties of PM steels are also reviewed.