Hybrid materials concepts

In transportation, lightweighting offers new solutions in the challenge of increasing fuel efficiency. Common methods in weight reduction include removing material from non-stressed areas, changing materials or product design, and changing heat treatment specifications. Another method is to move from a unitary material to a hybrid structure, which not only saves weight but also increases component functionality by combining matched materials in appropriate places.

Various joining processes can come into play for the production of multi-material forging blanks. Fusion welding processes become unfavourable when the materials differ in terms of their melting temperatures, e. g. steels and aluminium alloys. Solid-state welding processes are more robust because they use relatively low heat input and short process times. In addition, dissimilar materials can also be successfully joined by solid-state welding; and the occurrence and growth of brittle intermetallic phases in the joint interface can be kept to an acceptable level. Friction welding is a well-known solid-state welding process that combines the generation of frictional heat and pressure to produce a material bond.