Microstructural evolution and mechanical properties of braze joints in Ti-13.4Al-21.2Nb

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Welding Journal

OSTI ID:532975

Cadden, C H; Yang, N Y.C. ^[1]; Headley, T H ^[2]

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1. Sandia National Laboratories, Livermore, CA (United States)
2. Sandia National Labs., Albuquerque, NM (United States)

Braze joints in Ti-13.4Al-21.2Nb were made using several filler metal compositions based upon the Ti-Cu-Ni ternary system. Specimens were vacuum brazed, using filler metal preplaced between bonding surfaces. Two types of braze foil, one produced by rapid solidification techniques and one formed by a roll bonding process, were examined. Mechanical test results indicated that substantial differences in braze joint strength could be obtained from specimens prepared using foil manufactured by the two different processes. Specifically, for the higher alloyed composition, a laminated foil produced joints with lower room temperature tensile strength compared to its rapidly solidified counterpart. Specimens prepared using laminated foil typically failed through the braze joint and had low strength. This behavior was related to the presence of an increase amount of centerline alpha-two phase in the braze joints made using the laminated filler metals. The formation of this microstructural feature was influenced by segregation of the filler metal alloying elements, nickel and copper. Braze joints prepared using laminated foils exhibited higher levels of segregation, even after long hold times at the brazing temperature, than joints made using rapidly solidified foil.

• Research Organization: Sandia National Laboratory
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 532975
• Journal Information: Welding Journal, Journal Name: Welding Journal Journal Issue: 8 Vol. 76; ISSN 0043-2296; ISSN WEJUA3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
BRAZED JOINTS
EXPERIMENTAL DATA
FILLER METALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM ALLOYS
TITANIUM BASE ALLOYS