An oft-cited adage in industry is “whenever possible, avoid joining.” Often the discontinuity formed in a component during joining results in the creation of a weaker area, leading to lower performances there compared to the surrounding material. However, joints often cannot be avoided, and so different strategies must be proposed.

It is possible to choose between mechanical joining, such as clasps and latches; direct joining, i.e., welding; or indirect joining, such as brazing or adhesive joints. Any of these techniques can be used to join similar or dissimilar materials, but when the latter are bonded together, some additional challenges arise because of their different physical and/or chemical properties.