The mention of the word ceramic takes you to the world of earthenware, clay pots etc. found in many households. Treasured by both the owner and the maker, these products are made from naturally occurring clay and sand. With the advancement of technology, ceramic materials are now being manufactured in a laboratory under the watchful eye of a scientist. Made with a variety of ingredients and a number of processing techniques, ceramics are made into a wide range of industrial products.
Ceramics made through the above mentioned process are known as advanced ceramics or industrial ceramics. Their thermal stability, wear-resistance and resistance to corrosion of ceramic components make the application of ceramics the ideal choice for many industrial uses. Let’s look at a few:
Alumina is one of the most widely used advanced ceramic, and is made from aluminum oxide. This ceramic can be made via different types of manufacturing processes including isotactic pressing, injection molding and extrusion. Finishing can be accomplished by precision grinding and lapping, laser machining and a variety of other processes.
Alumina’s high ionic inter-atomic bond makes it chemically very stable, thereby making it a good electrical insulator. Further it is extremely resistant to wear and corrosion and has a high mechanical strength. Due to all these qualities, alumina components are used in semiconductor components, pump components, electrical insulations and automotive sensors.
This advanced ceramic is made from magnesium silicate and is a popular choice of material for insulators for electrical components. Other properties of steatite include excellent dielectric strength, low dissipation factor, and high mechanical strength. Further, due to Steatite’s excellent insulating properties it is used in thermostats and many other electrical household products.
Made from zirconium oxide, this ceramic has excellent strength and a high resistance to corrosion, wear and abrasion. Since it has a high tolerance to degradation, zirconia is the material of choice in the manufacturing of bearings and grinding. Further due to its high resistance to developing cracks, commonly referred to as ‘fracture toughness’, zirconia is used in structured ceramics, automotive oxygen sensors and dental ceramics.
Silicon Carbide Ceramic
When the grains of silicon carbide are bonded together through a process called sintering, they form a very hard ceramic. Due to its hardness, it is used in applications requiring high endurance such as car brakes, car clutches, ceramic plates and bullet proof vests.
Cordierite typically occurs in contact of argillaceous rocks. Cordierite has a very high thermal shock resistance and thus widely used in high temperature industrial applications such as heat exchangers for gas turbine.
Mullite is a very rare silicate material, formed at high temperatures and low pressure conditions. Its properties include low thermal expansion, low thermal conductivity, excellent creep resistance, suitable high temperature strength and outstanding stability under harsh chemical environments. It is commonly used in thermocouple protection tubes, furnace muffles and kiln rollers.