Cemented carbides and cermets

Cemented carbides were invented in the early 1920s at Osram (Germany), and first commercialized in 1926, by Krupp (Germany). They were an instant success, as they revolutionized the realm of metal machining tools, giving machining rates triple that of high-speed steels. Cemented carbide technology then spread rapidly throughout the world in the late 1920s, and soon it was being manufactured in the United States, the United Kingdom, Russia, Austria, and Sweden. Today, 100,000 t a year are manufactured, with China, the leading global producer. Cemented carbides uniquely combine high hardness and high toughness, and are among the strongest and highest modulus materials known. They see widespread usage in machining tools, excavation machinery, industrial processing machinery, and extreme armour-piercing munitions. While cemented carbide (tungsten carbide-cobalt) was the original “hardmetal” system, and remains the dominant one in the market today, cermet (titanium carbonitride) has a secondary market share in the industry. Invented at Krupp in the early 1930s, cermet has evolved significantly, from the original TiC-Ni concept to now WC-doped Ti(C,N)-Co. Even though TiC is harder than WC, and much cheaper and more readily available, cermet has more disadvantages than advantages, as discussed in this chapter. Therefore, in spite of the substantial evolution of cermet, it remains a minor player in the industry for reasons outlined in this chapter. This 16,000 word chapter with 90 references reviews in detail the evolution of cemented carbide and cermet, their properties, commercial applications, microstructure, and manufacture, including the latest research and commercial developments and market trends.