| 摘要 |
A braze foil (10) formed of a plurality of layers (12, 14, 16) of differing compositions wherein a combined melt of the foil has a desired braze composition, and wherein each layer is sufficiently ductile to be rolled into foil form, even though the desired braze composition is too strong or brittle to be fabricated as a foil. Each interface (18,20) between layers may establish a near eutectic composition for initiating melting at the eutectic temperature, with the layer thicknesses selected so that as melting progresses away from the interfaces, the near eutectic composition is maintained within the melt puddles. For certain nickel-based superalloy brazing applications, a foil having a layer of pure titanium, hafnium or zirconium may be sandwiched between respective alloy layers of 5-22% chrome - balance nickel |
