Ceramics can be friction welded to metals but the type of metal used has to be carefully selected. It is much easier to weld metals which have good plastic flow characteristics, for example aluminium, copper, lead, etc.
The ceramic may suffer thermal and mechanical shock, leading to cracking or fracture, if the metal used is resistant to plastic flow or requires a very large amount of heat to create plastic flow. Alternatively, friction welding with an insert can be used: for example, ceramic can be joined to steel by means of an aluminium insert which readily welds to both materials. In service, the soft aluminium insert helps to compensate for the mismatch in the thermal and general mechanical properties of the two parent materials.
Due to the nature of the materials involved, joints between ceramics and metals may have limited strength. Provided that designers make allowance for this, friction welding provides a successful solution to the difficult problem of joining these significantly different engineering materials.
FAQ: Is it possible to braze using friction-based processes?
FAQ: What is third-body friction joining?
For further information go to Joining Technologies.