Fluxless soldering with surface abrasion for joining metal foams

Fluxless soldering with surface abrasion has been developed for joining aluminum foams. To improve the wettability of the molten filler metal on the joined surfaces, 2 methods of abrasion were used to remove the oxide film from the aluminum foams prior to soldering. The effectiveness of the abrasion was determined by microstructure observation. The mechanical properties of the joints were examined by tension and compression tests. Assisting with the mechanical abrasion, fluxless soldering using a Zn-based alloy was proven suitable for joining aluminum foams. The joints showed no visible macroscopic deformation and did not cause the foam structure to collapse, which indicates a good wetting process. The mechanical properties of the joints were similar to the parent material, and a higher compressive strength was achieved. Fluxless soldering with surface abrasion not only offers an alternative means to join aluminum foams but also lays the foundation for joining metal foams by soldering.

► A method of fluxless soldering with surface abrasion was introduced to join aluminum foams.
► The metallurgical joint of aluminum foams was achieved, and interdiffusion occurred.
► Surface abrasion was suitable for wetting process.