Low-Temperature Large-Area Brazing of Titanium Structures.

Various brazing filler metals were identified and brazing processes established for producing large-area damage-tolerant laminates of Ti-6Al-4V, Ti-6Al-6V-2Sn, and Ti-3Al-8V-6Cr-4Mo-4Zr (Beta C) for service between 227 K and 422 K (-50F and 300F). Low melting-temperature filler metals were identified to permit the fabrication of laminates in the STA condition. Brazing filler metals were screened based upon their flow temperature and behavior, lap shear strength, bend deflection, and corrosion resistance. The most attractive brazing filler metals were aluminum brazing sheet 22 and alloys from the Al-Cu-Ag system. The brazing sheet was placed between the lamina and the Al-Cu-Ag alloys were placed alongside the lamina and flowed into the joints.