| Themultilayering method and subsequent heat treatment process were used to prepare multi- layer composite foils of silver-copper-tin medium temperature brazing filler. The microstructures, melting characteristics, mechanical properties, phase composition and brazing properties of the prepared foils were tested. The results showed that the brittleness of the foils was obviously improved, as illustrated by the fact that they could be blanked into a shape of certain thickness and specific size at room temperature. The continuity of the lamellar structure was obviously influenced by the layered arrangement, and the metals were alloyed during the composite process of large deformation rolling, producing intermediate compounds, which is accompanied by the elongation of the grains. Consequently, the multi-layer silver- copper-tin brazing filler metal displayed excellent a wetting and spreading ability on copper and nickel substrates, endowing the resulting brazed copper and nickel joints with preferable mechanical properties. |
