Flux-free brazing of aluminum alloys was carried out using the clearance filling test. The influences of additives to the core material and brazing filler alloys, heating time of the sample, and oxygen partial pressure of atmospheric gas were investigated with the aim of improving the flux-free brazability. The flux-free brazability of the aluminum alloys was much improved by adding some magnesium to the sample. When the oxygen partial pressure of atmospheric gas was much reduced to the order of 10~(-30)atm by using zirconia oxygen pump, a good brazability was obtained even after a long heating of the sample.
展开▼
