Ferrous and nonferrous structural precision parts comprise about 80% in tonnage of powder metallurgy mass products. Of these parts, roughly 75% are used for transportation, primarily in the automotive industry, in which case particularly high requirements towards mechanical and functional properties, shape precision, and surface finish have to be met. In this area, powder metallurgy mass production is highly competitive to conventional metalworking techniques.

Here however it should be kept in mind that the production of components from wrought steels, cast iron, and various nonferrous alloys is done mostly by well established machining techniques with geometrically defined, in part also undefined, cutting edges. These machining processes have been revolutionized by the introduction of hardmetals, a special PM product, and of related, still harder cutting materials. This group of materials, for which PM is the only feasible manufacturing route, in production value even exceeds the PM precision parts, underlining the technical and economical importance of powder metallurgy products in general.

The competitiveness of PM precision components is enhanced by secondary operations which improve mechanical, functional, and geometrical properties. Among those operations, machining seems to be the most complicated and least understood and at the present time is not sufficiently managed. Machining of PM parts, employing different cutting methods, extends the range of shapes and thus also the range of applications without lowering the standard for static and especially dynamic mechanical properties, shape, geometrical precision, and surface finish. This latter precondition is an essential point when studying PM parts machining.

As mentioned...