Table 14.1 presents typical examples of products obtained by ceramic powder processing. Nowadays, ceramic-ceramic composites are used for many engineering applications. Development of ceramic-ceramic composites is largely due to improvements in microstructure of reinforced ceramics such as Al2O3 + TiC, Al2O3 + ZrO2, ZrO2 + Al2O3, and whisker-reinforced ceramics such as Al2O3 + SiCw, Si3N4 + SiCw, etc. Among these, Al2O3 + ZrO2 and ZrO2 + Al2O3 are referred to as toughened ceramics, which have widened the scope of application of oxide ceramics.
One of the main oxide ceramics is alumina, also called corundum. Emery is also a widely used oxide ceramic. It has high hardness and moderate strength. Aluminum oxide is almost totally manufactured synthetically in order to control quality.
Products Obtained by Ceramic Powder Processing [Malkin 1989]
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Group of Applications Products Obtained by Ceramic Powder Processing
Synthetic aluminum oxide, first made in 1893, is used for applications such as electrical and thermal insulation and as cutting tools and abrasives [Ruhle 1985].
Zirconia (zirconium oxide, ZrO2) has high toughness, high resistance to thermal shock, wear, and corrosion, low thermal conductivity, and a low friction coefficient when paired with many materials [Green and Hannink 1989].
Zirconia-toughened alumina (ZTA) is a ceramic system obtained as a result of the transformation toughening of ZrO2 in a constrained matrix of Al2O3. One field of application for ZTA due to excellent wear behavior is the application for cutting tools. In recent decades ceramic cutting tools have made a strong impact in manufacturing.