What Are Ceramics?

What is the main differences between the properties of engineering ceramics and traditional ceramics?

• Answer:

  The short answer is that technical or engineered ceramics have optimized properties along one or more characteristics so that they better fit the application. Traditional ceramics are characterized as typically a vitreous bond based system. This limits the application of traditional ceramics in high strength, high fracture toughness, high temperature applications. The glass bond is the limiting parameter. Also traditional ceramics are limited to the oxide forms of metals which rules out carbide, nitride and other exotic molecules. Triaxial porcelains is the most widely produced traditional ceramic. It is the basis for the majority of every day items from house wares through sanitary ware. It is produced from blending common clays, Kaolin, Ball Clay and Feldspar and Flint to yield a high quality material that serves as an excellent foundation for a wide variety of products. Engineered Ceramics are typically formed from high purity materials and primarily depend on sintered bonds. Glass if it is present is intentionally designed into the system. Materials such as Silicon Carbide can be fabricated to take advantage of a variety of its unique properties. The material can be blended to produce heating elements because of its electrical conductivity. It is formed to make refractories because of its resistance to melting at high temperature. It is also used as a cutting material because it is almost as hard as diamond. Zirconium Oxide can be blended with other oxides such as Yttrium Oxide to produce materials with high fracture toughness as well as oxygen sensors. Aluminium Oxide is the base for a wide variety of products from electrical applications where its low resistance is crucial to polishing applications where its abrasiveness is desirable.