Patent ID: 7537809
Filing Date: 2009-05-26
Classification: C23C,F01D,Y02T

Abstract:
1. A method for coating a rotatable member of a turbine or a compressor with an abrasive coating film in order to minimize clearance between the rotatable member and an opposite component of the turbine or the compressor, the method comprising the steps of: (a) generating a pulsed discharge between a rotatable member formed into a predetermined shape and a first discharge electrode in a dielectric liquid or gas, wherein the first discharge electrode is a green compact electrode; (b) transferring a first coating material from the first discharge electrode onto the rotatable member by each discharge pulse so that the abrasive coating film is formed on the rotating member, wherein when the abrasive coating film formed by the first coating material rubs against the opposite component the abrasive coating film shaves the opposite component, wherein the green compact electrode includes the first coating material or a second material that changes into the first coating material due to the discharge, and the first coating material is one of, or a mixture of, cBN, TiC, TiN, TiAlN, TiB (c) forming, on the rotatable member, the abrasive coating film by repeatedly generating the discharge pulse, wherein the rotatable member is a turbine blade, a compressor blade or a labyrinth seal; and (d) deploying the rotatable member in the turbine or the compressor, wherein the rotatable member is disposed so that there is a clearance between the rotatable member and the opposite component of the turbine or the compressor so that the abrasive coating film shaves the opposite component when the abrasive film rubs against the opposite component thereby minimizing the clearance between the rotatable member and the opposite component.