Ceramics at TWI

Adhesives

Adhesive bonding can be used to produce joints between ceramics and themselves or metals. For relatively low temperatures, (<300°C), organic adhesives will suffice; however, for high temperature capabilities (>1000°C), inorganic adhesives are required.

The bonds are produced by careful preparation of the substrate surfaces and then the adhesive layer is applied. The whole assembly is then cured, which can require temperatures from 260-1000°C.

The inorganic adhesives are generally composed of constituents such as: alumina, zirconia, silica, magnesia, phosphates and silicates. The ingredients are mixed in order that a range of thermal expansions or operating temperatures may be achieved. Consideration must be taken into account regarding joint design.

Joint assessment can be made using:

Scanning electron microscopy (SEM) and optical examination
Mechanical testing
Non-destructive testing (NDT) via thermal imaging

Further information

Best practice guides: Joining ceramics - a guide to best practice
Knowledge summaries: Ceramic Adhesives
FAQs: What are ceramic adhesives?; What are inorganic ceramic adhesives?
Staff papers: Techniques for bonding ceramics (Bulletin, September/October 1990) Industrial Members Only