Gallium Distribution in Gallium-Coated Aluminum for Brazing Application
This work deals with the study of a new aluminum brazing process, called Galluminium. This technique, consisting in using gallium as a solder, is advantageous since it enables to braze at ambient air without flux. Indeed if the gallium coating is done mechanically, it descales the alumina layer and acts as a barrier against further reoxidation. Nevertheless, liquid gallium causes a severe aluminum embrittlement since it penetrates into the aluminum grain boundaries. We will show in this paper that this phenomenon has only a little impact on the mechanical resistance of the brazed joints since the amount of deposited gallium is enough low to avoid a severe embrittlement and the heat treatment (from 200°C to 600°C during several minutes) during brazing process dissolves gallium in the bulk.
B.S. Bokstein, A.O. Rodin and B.B. Straumal
E. Ferchaud et al., "Gallium Distribution in Gallium-Coated Aluminum for Brazing Application", Defect and Diffusion Forum, Vols. 309-310, pp. 255-260, 2011