A method of forming a curved-shaped processing hole in a workpiece by electromechanical machining includes a step of feeding an electrolytic solution through an inner channel of a processing electrode and jetting the electrolytic solution from an outlet opening of the inner channel disposed on a tip surface of the processing electrode, a step of applying a potential difference between the processing electrode and the workpiece while jetting the electrolytic solution from the outlet opening of the processing electrode, and a step of forming the curved-shaped processing hole in the workpiece. In the jetting step, at least one of a current density distribution on the tip surface of the processing electrode or a flow velocity distribution of the electrolytic solution jetted from the outlet opening is eccentric to a downstream side of a curving direction of the processing hole with respect to an axial center of the tip surface.

A repair method for a gas turbine blade comprises: a step of removing a thermal barrier coating to expose at least part of a base material of the gas turbine blade; a first etching step of etching the exposed base material; a first identification step of identifying a base material deterioration layer that is harder than the base material from the etched base material; a first removal step of removing the identified base material deterioration layer if the base material deterioration layer is identified in the first identification step; and a step of applying a thermal barrier coating to the exposed base material after it is determined that there is no base material deterioration layer in the first identification step, or after the base material deterioration layer is removed in the first removal step.

A repair method for a gas turbine blade comprises: a step of removing a thermal barrier coating to expose at least part of a base material of the gas turbine blade; a first etching step of etching the exposed base material; a first identification step of identifying a base material deterioration layer that is harder than the base material from the etched base material; a first removal step of removing the identified base material deterioration layer if the base material deterioration layer is identified in the first identification step; and a step of applying a thermal barrier coating to the exposed base material after it is determined that there is no base material deterioration layer in the first identification step, or after the base material deterioration layer is removed in the first removal step.

A method for making a three-dimensional hierarchical layered porous copper, the method includes providing a copper-zinc alloy precursor being composed of a β′ phase and a γ phase, and treating the copper-zinc alloy precursor by electrochemical dealloying. The present application further provides a three-dimensional hierarchical layered porous copper including a first surface layer, an intermediate layer, and a second surface layer stacked in that order. The first surface layer includes a plurality of micron-scale pores and a plurality of first nanoscale pores. The intermediate layer includes a plurality of second nanoscale pores. The second surface layer includes the plurality of micron-scale pores and the plurality of first nanoscale pores.

A method of removing an aluminide diffusion coating from a gas turbine engine component having a nickel alloy base material may comprise: disposing the gas turbine engine component in a solution, the solution including an acid between 5% and 15% vol./vol. and water between 85% and 95% vol./vol.; placing the gas turbine engine component in electrical contact with a graphite plate; and removing the aluminide diffusion coating from the gas turbine engine component in response to placing the gas turbine engine component in electrical contact with the graphite plate and disposing the gas turbine engine component in the solution.

A method of removing an aluminide diffusion coating from a gas turbine engine component having a nickel alloy base material may comprise: disposing the gas turbine engine component in a solution, the solution including an acid between 5% and 15% vol./vol. and water between 85% and 95% vol./vol.; placing the gas turbine engine component in electrical contact with a graphite plate; and removing the aluminide diffusion coating from the gas turbine engine component in response to placing the gas turbine engine component in electrical contact with the graphite plate and disposing the gas turbine engine component in the solution.

A substrate processing apparatus includes a substrate rotator, a processing liquid supply, an anode and a cathode, and a controller. The substrate rotator is configured to hold and rotate a substrate. The processing liquid supply is configured to supply a processing liquid to the substrate held by the substrate rotator. The anode and the cathode are configured to apply a voltage to the processing liquid supplied from the processing liquid supply. The controller is configured to control the substrate rotator, the processing liquid supply, and the anode and the cathode. The controller allows, by contacting the anode and the cathode with the processing liquid independently, the processing liquid in contact with the anode and the processing liquid in contact with the cathode to be supplied to the substrate while being spaced apart from each other when the substrate is rotated.

A method for treating a surface of a metallic structure, the metallic structure being made of a first metallic material, the method including the steps of: (a) releasing metallic ions from the surface of the metallic structure; and (b) depositing a nano-structured metallic layer onto the surface of the metallic structure from the released metallic ions, wherein the nano-structured metallic layer includes uniform nanoparticles.

Systems and methods for electroless plating a first metal onto a second metal in a molten salt bath including: a bath vessel holding a dry salt mixture including a dry salt medium and a dry salt medium of the first metal, and without the reductant therein, the dry salt mixture configured to be heated to form a molten salt bath; and the second metal is configured to be disposed in the molten salt bath and receive a pure coating of the first metal thereon by electroless plating in the molten salt bath, wherein the second metal is more electronegative than the first metal.

Systems and methods for electroless plating a first metal onto a second metal in a molten salt bath including: a bath vessel holding a dry salt mixture including a dry salt medium and a dry salt medium of the first metal, and without the reductant therein, the dry salt mixture configured to be heated to form a molten salt bath; and the second metal is configured to be disposed in the molten salt bath and receive a pure coating of the first metal thereon by electroless plating in the molten salt bath, wherein the second metal is more electronegative than the first metal.