Joint characterisation for repair brazing of superalloys

The restricted weldability of superalloys that can operate at high temperatures and under mechanical loadings, required in modern gas turbines, has lead to the development of repair brazing techniques for various crack types and for restoration of dimensional changes. Methods to characterise these joints are necessary for the development work, the quality control of the procedures and acceptance of refurbished parts. These methods are mainly various NDT techniques, metallography, mechanical testing and service simulating testing, such as creep and thermal fatigue testing.