CERAMICS TECHNOLOGY

By: Vaibhav A. Chilate Ceramics are a group of materials which are produced by compacting the powders into a green body followed by heating to a certain temperature so that the particles get bonded together called as sintering.<br>Ceramics possess good refractory strength, chemical resistivity and physical strength. Electrical industry uses ceramics for their good insulating properties. Many of them are used as dielectric materials in capacitors, etc.<br>Ceramics are manufactured from their powders. First and foremost step is to obtain the powders. There are several methods by which the powders are obtained such as spraying, ball milling, grinding, etc. which obtain different sizes and shapes of powder particles. Secondly, these powders are blended according to the requirements of the application and desired properties of the product. The process of blending of powders is carried out to obtain uniformity, since the powders made by various processes may have different shape and sizes and to impart special physical and mechanical properties. In order to avoid contamination and deterioration, powder mixing must be carried out under controlled conditions.<br>Third step is shaping the powders into the product shape by adding suitable binder to them. And fourth step is to sinter these powders up to certain temperature to bring about particle atomic diffusion and hence the bonding between particles.<br>Compared to other materials they are economical for their strength and hardness. Compressive strength is good. Some ceramics are bio – ceramics. They are used to produce dental implants, synthetic bones and prostheses. Automobile industry uses them for their use as insulator in spark plug and discs for the disc brakes. Due to their hardness, they are also used in manufacturing metal cutting tools. Chemical resistivity is another good property exhibited by the ceramics, thus they are used as lining for the pipes and containers which carry chemical liquids and slurries.