Method of making replacement airfoil components

A method of repairing one or more turbine components having a first surface and a second surface which are spaced apart along a longitudinal axis, comprising the steps of:

• a) identifying a portion of the component to be repaired;
• b) defining a cutting path on the component around said portion, said cutting path including a plurality of projections and corresponding sockets;
• c) excising said portion from the component along said cutting path using a non-conventional machining process to leave a first tapered bonding surface positioned between the first surface and the second surface on said component corresponding to at least a portion of said cutting path wherein said tapered bonding surface tapers along the longitudinal axis, said machining process conducted so that a cutting kerf is taken from the excised portion;
• d) forming a replacement member having outer dimensions corresponding to said cutting path and having at least one projection or socket, said replacement member having a second tapered bonding surface for mating with the first tapered bonding surface on the component, said replacement member further having outer dimensions which compensate for the now removed cutting kerf;
• e) inserting said replacement member into the component to align said first and second tapered bonding surfaces and mechanically interlock said projections and corresponding sockets, with the outer dimensions of said replacement member enabling a close fit and predictable joint control between the replacement member and said component;
• and
• f) securing said replacement member in the component by a metallurgical joining process.

A method of repairing turbine vane sections having a first surface and a second surface which are spaced apart along a longitudinal axis, including airfoils and flowpath walls, comprising the steps of:

• a) identifying a portion of the vane section to be repaired;
• b) defining a cutting path on the vane section around said portion, said cutting path including a plurality of rounded projections and corresponding sockets;
• c) excising said portion from the vane section along said cutting path using computer numerically controlled continuous wire electrical discharge machining to leave a first tapered bonding surface positioned between the first surface and the second surface on said vane section corresponding to the rounded projections or corresponding sockets thereon wherein said tapered bonding surface tapers along the longitudinal axis, said machining conducted so that a cutting kerf is taken from the excised portion;
• d) storing data representing said cutting path in a computer program;
• e) forming a replacement member by executing said computer program to cut the replacement member from a blank using continuous wire electrical discharge machining, said replacement member thereby having at least one projection or socket and a second tapered bonding surface for mating with said first tapered bonding surface, with outer dimensions which correspond to said cutting path and which compensate for the now removed cutting kerf;
• f) inserting said replacement member into the vane section to align said first and second tapered bonding surfaces and mechanically interlock said projections and corresponding sockets, with the outer dimensions of said replacement member enabling a close fit and predictable joint control between said replacement member and the vane section;
• and
• g) securing said replacement member in the vane section by a metallurgical joining process.