ABSTRACT
With lightweighting becoming an increasingly popular practice, being able to assemble dissimilar materials, such as plastics, composites, and metals, is becoming a more important issue. Since aluminum is the most common material used in lightweight mechanical applications, joining technologies used for the assembly of aluminum parts for automotive applications is a growing subject.
Materials joining is based upon three principles:
Material coalescence
Interlocking joints
Frictional connection
For material coalescence, the materials are held together by atomic or molecular binding forces. In this case, the atoms and/or molecules must be placed in close proximity to each other by processes without the presence of heat (solid-state welding or diffusion), processes based on the mixing in a liquid state (fusion welding), or processes with and addition of a third, generally hardening, liquid substance (soldering or adhesive bonding. Interlocking joints are formed by the interlocking of two materials or by the anchoring of additional elements into or inside the corresponding materials (mechanical joints). Frictional connections are the result of friction between the involved materials, enhanced by the application of an external force (shrinking a hub onto a shaft).
