Many products using Cu such as heat exchangers and electrical wire have been developed, because of high thermal conductivity and electrical conductivity. In recent years, the combination of Cu and Al has been promoted to reduce weight and improve strength. Generally, metallurgical joining using pressure welding or welding is employed for joining dissimilar metal materials. However, most of them have a limited joint design and have a problem that they cannot cope with complicated ones.

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... this time, we will try to join with brazing that can handle complicated joint design by a relatively simple method. On the other hand, there are various problems with brazing of dissimilar metals. In the brazing of Al/Cu, an intermetallic compound is formed at the interface, resulting in a problem that the mechanical properties deteriorate. Furthermore, there is a few gap temperature in liquidus temperature between Al-Si brazing filler metal and Al-base metal. Therefore, temperature control is very important when brazing Al and Cu. In this study, an Al plate and a Ni-plated Cu pipe were brazed using a brazing furnace capable of highprecision temperature control. As a result, it was found that the appropriate brazing temperature was 858 K. From this, a sound brazed joint could be obtained. Heating time influenced strongly spreading ability of molten brazing filler metal and fillet formability at the brazed joint.