229 Improvement of brazeability of dissimilar joints of aluminum alloys to stainless steel in the air

In order to investigate the reason why the brazing of dissimilar metals between aluminum alloys and stainless steel in the air, the brazing of various aluminum alloys to stainless steel were carried out using Al-Si brazing filler and the behavior of brazed interface was examined. As the result, the cause to make the brazing difficult is shown that the brazing filler is rapidly solidified isothermally due to the invasion of Zn into the brazing area from the flux, before the wetting of the brazing filler to stainless steel. Based on these phenomena, the two types of new joining method that brazing could be made were suggested and the practical applicability was tried.