| abstract |
A process for diffusion bonding of cracks (10) and other gaps (10) in high-temperature nickel and cobalt alloy components (12) is described. The gap (10) is filled with alloy powder (14) matching the substrate alloy, or with an alloy of superior properties, such as MAR-M 247, MAR-M 247LC, or CM 247LC. A braze (16) containing a melting point depressant is either mixed into the alloy powder (14) or applied over it. The depressant is preferably hafnium, zirconium, or low boron. The component (12) is heated for 15-45 minutes above the melting point of the braze (16), which fills the spaces between the alloy powder (14) particles. The component (12) is diffused at a temperature above or below the liquidus of the braze (16) and solution heat-treated and aged at a temperature at which the braze (16) and alloy mixture in the gap (10) is solid, but the depressant diffuses away. |