Interfacial reaction between alumina and Cu-Ti filler metal during reactive metal brazing

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Welding Journal (Miami); (United States)

OSTI ID:5041111

Bang, K S ^[1]; Liu, S ^[2]

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1. Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of). Welding Research Center
2. Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research

If a chemical reaction at the interface can influence significantly the properties of a brazed joint using reactive filler metals, it is very important to understand which reaction occurs and how the reaction products grow at the interface. In this research, the interfacial reaction and the kinetics of reaction products growth in alumina brazing utilizing Cu-Ti filler metals were investigated. Cu-Ti filler metals reduced Al[sub 2]O[sub 3] to form TiO at the interface. Thermodynamically, reduction of Al[sub 2]O[sub 3] is possible through the dissolution of the aluminum by the filler metal. At 1,300 K, for example, interfacial reaction can proceed until the activity of aluminum reaches about 0.02 in Cu-20 at.-% Ti filler metal. With time, the TiO layer grew toward the center of the brazing filler metal following a parabolic rate law, at the cost of another complex oxide, presumably Ti[sub 3]Cu[sub 3]O, which formed next to the TiO. The activation energy of TiO growth was 208 kJ/mol (50 kcal/mol), which corresponds to the activation energy of oxygen diffusion in the TiO. Therefore, it appears likely that the growth of TiO is controlled by oxygen diffusion.

• OSTI ID: 5041111
• Journal Information: Welding Journal (Miami); (United States), Journal Name: Welding Journal (Miami); (United States) Vol. 73:3; ISSN 0043-2296; ISSN WEJUA3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BRAZED JOINTS
BRAZING
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER ALLOYS
FABRICATION
FILLER METALS
INTERFACES
JOINING
JOINTS
OXIDES
OXYGEN COMPOUNDS
TITANIUM ALLOYS
USES
WELDED JOINTS
WELDING