The advantages of modern engineering ceramics are following below :
- Most of the ceramics possess high hardness due to strong covalent bonds between atoms in their crystal structure.
- Ceramics have high melting points because of this advantages it used for the lining of the furnaces.
- Ceramics are good thermal insulators hence it possess excellent insulating property.
- Ceramics have extremely high electrical resistivity hence they are used for electrical insulators.
Note : Alumina is used for spark plug insulation.
- The densities of ceramics are low as compared to other engineering material. This results in lightweight components.
- Ceramics are chemically resistance to most of the acids, alkalis and organic substances this increases durability of the ceramics components.
Disadvantages of ceramics :
- Ceramics are brittle in nature hence brittle fracture in cast iron components.
- They are highly susceptible to stress concentration.
- In ceramics ductility is almost zero because of presence of small voids in the structure of ceramics parts.
- Ceramics have poor tensile strength.
- Ceramics are difficult to shape and machine.
We will see the advantages and disadvantages of ceramics but a number of parts of automotive engines are now a days made of ceramics include cylinder liners, pistons, valves and engine blocks.
Therefore the principle advantages of ceramics engine components over conventional metal parts are also interesting that we have to discuss.