12 - Alumina as a wear-resistant industrial ceramic

Abstract

Alumina is the most widely used wear-resistant ceramic, due to its unbeatable combination of low cost, high wear resistance, and high corrosion resistance. For example, in the wear-resistant ceramics realm, silicon carbide is about three times the cost of alumina and tungsten carbide about four times the cost. Alumina is tougher than silicon carbide but less tough than tungsten carbide. For most applications discussed in this chapter, the toughness of alumina is more than sufficient. Tungsten carbide is used in expensive niche applications where toughness is critical. Moreover, as discussed in Chapter 4, zirconia-toughened alumina (ZTA) rivals the toughness of tungsten carbide, at a much lower cost than tungsten carbide, but a higher cost than pure alumina. The primary commercial application of ZTA is in orthopedics although it is beginning to see some use in dentistry and industrial wear-resistant applications. In time ZTA may significantly supplant tungsten carbide in the wear-resistant industry, but it will never supplant pure alumina, which dominates the wear-resistant industry because of its unique combination of low cost and high performance. This chapter begins with a detailed treatise on the tribology of alumina. This is followed by a case study based on the industrial alumina technology of Taylor Ceramic Engineering (alumina specialty manufacturer for over 40 years). Alumina industrial wear and corrosion resistant ceramics service a diversity of industries, particularly mining, but also including textiles, wire drawing, food and beverage, papermaking, heavy clayware industry, pumps, seals, and general engineering.