A ceramic is
non-metallic, inorganic, crystalline oxide of nitride or carbide material.
These materials are hard, brittle, and sturdy in compression and posses weak
shear tension. When subjected to acidic or caustic environments, these can
withstand chemical erosion. The most common type advanced ceramic materials
are- Silicon Carbide, Alumina and Zirconia.
Methods of machining ceramic products involve:
- Hot Pressing
- Dry Pressing
- Cold Static Pressing
- Extrusion
- Sintering and firing
- Hot pressing: This method involves application of pressure at high temperatures, to reduce voids. It helps in production of dense sintered bodies. It yields Thermal Conductivity Ceramics bodies of simple shapes.
- Dry Pressing: In this machining method, filling of the die is done with dried and granulated raw materials. Granulated raw materials fill a metallic mold cast and pressure is applied from the top. This method is ideal for mass-production of semi-complex machinery parts.
- Cold static Pressing: In this technique of machining ceramic, the granulated raw materials are poured into a rubber casting mould. This is later are subjected to hydraulic pressure, the pressure if applied evenly from all directions, results in Isostatic pressing.
- Extrusion: In Extrusion method dried and granulated raw materials are mixed with water and binder, plasticizing agent and dispersing agent. The resulting clay body is then extruded to final shape. This method is ideal for Thermal Conductivity Ceramic having a long product having continuous cross-sections.
- Sintering or firing: During the firing or sintering process, raw materials are heated below their melting point temperature to produce a sinter powder. Depending on the intended application, sintering methods are of types —vacuum sintering, atmosphere sintering and non-oxidizing sintering.
