History of Development of Cemented Carbides and Cermet Keiichi

The performance of cutting tool materials has been continuously enhanced in response to users’ needs for higher cutting speed. The first high-speed steel appeared on the market in the beginning of the 1900s. At present, cemented carbide accounts for the majority of cutting tool material because it can cut workpieces at a higher speed than high-speed steel as shown in Fig. 1. In the latter half of the 1970s, cemented carbide tools coated with alumina or titanium compound were developed and they enabled a far higher cutting speed. Meanwhile, cermet is a composite material consisting mainly of a hard titanium phase. Although cermet was originally developed for use as a jet engine material, it has evolved as a cutting tool material separately from other tool materials because of its low reactivity with steel and fine cutting surface. The percentages of currently used cutting tool materials (indexable inserts) are shown in Fig. 2. This paper describes the development and history of cemented carbide and cermet.