Brazing is a powerful and well established technique in joining aluminium heat exchangers. In order to ensure sufficient brazing performance flux is commonly employed. Some products, however, cannot tolerate any flux residues on surfaces outside or inside the finished heat exchanger. Possible incompatibility with cooling agent and corrosion issues are the main driving force to reduce the usage of flux. Along these lines, there is a general goal to reduce the number of process steps as well as good environmental and valid safety reasons to avoid flux. With the intention to meet the ever increasing demand for flux free brazing, several solutions have been developed in recent years. In this contribution the advances in flux free brazing will be presented and discussed.
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