Gas Turbine Sealing Interface Repair Using Boron-Modified Preform

A preform made of parent metal (cobalt or nickel) is positioned at the damaged sealing interface before applying the repair material. This preform serves as a sacrificial layer that will diffuse the additive material away from the critical sealing interface area during the heating process, thereby preserving the melting point and temperature resistance of the repaired sealing interface.

The preform acts as an intermediary between the repair material and the parent metal component. It facilitates the controlled diffusion of additive material (boron) away from the sealing interface while allowing the repair material to bond to the parent metal, thus mediating the trade-off between repair effectiveness and temperature resistance preservation.

The preform creates a non-uniform distribution of additive material concentration. The area near the sealing interface has lower additive concentration (higher temperature resistance) while the preform area has higher additive concentration (enables bonding). This local quality variation resolves the contradiction between achieving strong bonding and maintaining temperature resistance.

The solution moves the problem from a two-dimensional surface repair to a three-dimensional volume control by introducing the preform as a separate volumetric element. The additive material diffusion is controlled in the depth dimension through the preform, allowing surface properties (temperature resistance) to be preserved while bulk bonding strength is achieved.