No CrossRef data available.
Article contents
Infrared Joining of Titanium Aluminides by Using Ti-15Ni-15Cu Foil
Published online by Cambridge University Press: 10 February 2011
Abstract
The infrared joining of titanium-aluminides Ti50A150, Ti60Al40 and Ti70A130 at Tw= 1100∼1200°C for 30–60sec using Ti-15Cu-15Ni foil as brazing filler-metal was investigated. Multilayered structures are formed by isothermal solidification following solid-state interdiffusion. The diffusion of Al atoms is the main controlling factor pertaining to the microstructural evolution of the joint interface. Seven characteristic zones at Tw can be distinguished in the Ti50Al50 joint: γ-TiAl (I and II), α + β two-phase mixed, high Al% α-phase, α2-Ti3Al, β-Ti and residual liquid filler-metal. Five characteristic zones at Tw, are obtained in the Ti70A130 joint: α2-Ti3Al, α2 + β two-phase mixed, α + β two-phase mixed, β-Ti and residual liquid filler-metal. The observed joint microsturctures at room temperature are obtained from the phase transformation of these well-established high-temperature phases during cooling. A step-by-step microstructural evolution mechanism at Tw = 1150°C is proposed individually for Ti50A150 and Ti70A130 alloys. These steps are in good agreement with the observed microstructures and are consistent with the multiphase diffusion theories in solid-state systems. The microstructural evolution of Ti60A140 joint interfaces can also be explained by the proposed step mechanisms for Ti50A150 and Ti70A130 alloys.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 1999