Introduction – Ceramics

The word ‘ceramic’ is originated from greek word keromikos, which means ‘burnt stuff’.

Ceramics are compounds of metallic and non-metallic elements.

Characteristics of ceramics are:

-high temperature stability

- high hardness - brittleness

- high mechanical strength

- low elongation under application of stress

- low thermal and electrical conductivities

Classification – Ceramics

Ceramics are classified in many ways. It is due to divergence in composition, properties and applications. 

Based on their composition, ceramics are: 

- Oxides

- Carbides 

- Nitrides

- Sulfides

- Fluorides

etc.

 Based on their specific applications, ceramics are classified

as:

- Glasses

- Clay products

- Refractories

- Abrasives

- Cements

- Advanced ceramics for special applications

Based on their engineering applications, ceramics are classified into two groups as: traditional and engineering ceramics.

 Traditional ceramics – most made-up of clay, silica and feldspar

Engineering ceramics – these consist of highly purified aluminium oxide (Al2O3 ), silicon carbide (SiC) and silicon nitiride (Si3N4 )