Low-temperature Filler Metals

We also have experience in the application of aluminum-based filler metals for brazing titanium at low temperature in vacuum or in air (Table 3-1) either for manufacturing structural joint or for repair purposes. These brazing filler metals are supplied in the form of wire or foil (Table 3-2). Strength of titanium brazed joints is presented in Table 3-3.
Aluminum-based brazing filler metals are based on Al-Cu, Al-Mg, Al-Cu-Si eutectics, and modified with Cr and Ti to refine microstructure of brazing joints, and with Beryllium to suppress an ignition during the torch brazing. These filler metals can be used for torch brazing of thin-wall titanium or aluminum articles, for example, for brazing tubing, and repairing fin-plate heat exchangers or honeycomb structures. Torch brazing is carried out with proprietary non-toxic fluxes TBF-42 or TBF-60 based on fluoride and chloride systems.
Brazing filler metals listed in Tables 3-1 and 4 are suitable for vacuum brazing of titanium at the temperatures significantly lower than conventional silver-based and titanium-based filler metals. For new applications and for brazing dissimilar metals, we still recommend evaluation of wetting and gap filling abilities of these new filler metals, as well as testing the strength of brazed joints.
Pictures followed after Tables represent examples of brazed joints made using Aluminum-based filler metals: titanium-to-titanium and titanium-to-copper.