Joining aluminum and steel today is still challenging. The large difference of melting points ofAl and Fe and the rapid formation of fragile intermetallic compounds (IM) make the welding ofAl-based and Fe-based alloys at most very difficult if not impossible. Nonetheless, the need ofsuch joints is growing since one tends to incorporate more and more aluminum parts asreplacement of “low stressed” steel parts in order to achieve lightweight structures, especially intransportation industry. Here the idea is to depose a thick (mm) layer of aluminum on the steelusing a powder additive manufacturing process: the cold spray. Aluminum powder is blowntoward the steel using pressured gas at rather low temperature (around 80°C). The aluminum partis then welded to the additive manufactured aluminum layer on the steel using conventional laserwelding. In the second part of this presentation copper deposition using cold spray is used onthin PCB conductors to allow laser welding of connectors.
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