ABSTRACT
Engineering materials have been recently developed. Their hardness and strength are considerably increased, such that the cutting speed and the material removal rate (MRR) tend to fall when machining such materials using traditional methods like turning, milling, grinding, and so on. In many cases, it is impossible to machine hard materials to certain shapes using these traditional methods. Sometimes it is necessary to machine alloy steel components of high strength in a hardened condition. It is no longer possible to nd tool materials that are sufciently hard to cut at economical speeds, such as hardened steels, austenitic steels, Nimonic, carbides, ceramics, and ber-reinforced composite materials. The traditional methods are unsuitable to machine such materials economically, and there is no possibility that they can be further developed to do so because most of these materials are harder than the materials available for use as cutting tools.
