Ceramics at TWI

Mechanical joining of ceramics

A range of mechanical techniques can be used to incorporate ceramic components into metallic structures. Technically, mechanical joints are simple in design, using bolts or screw threads. However, even simple design requires complex diamond machining, which makes such joints expensive; moreover, they will not be gas tight.

Shrink and taper fitting exploit the difference in thermal expansion between the metal and ceramic components. The joint is formed at high temperatures; the metal surrounds the ceramic component and contracts on cooling. As the temperature falls the metal clamps the ceramic, so forming a strong joint. Obviously, this kind of bond can be used only at low temperatures and can be subject to failure at local stress concentrations.

Further information

Best practice guides

• Joining ceramics - a guide to best practice

Staff papers

• Techniques for bonding ceramics (Bulletin, September/October 1990) Industrial Members Only

For more information please contact: ceramics@twi.co.uk