An electrolyte for electrochemical machining of a γ-γ′ nickel-based superalloy includes NaNO.sub.3 at a content of between 10 and 50% by weight relative to the total weight of the electrolyte; an additive chosen from KBr, NaBr, KI, NaI and mixtures thereof, in an additive/NaNO.sub.3 molar ratio of between 1 and 15; optionally an ethylenediaminetetraacetic acid-based complexing agent at a content of between 1 and 5% by weight relative to the total weight of the electrolyte at a pH of between 6 and 12; optionally an anionic surfactant at a content of between 1 and 5% by weight relative to the total weight of the electrolyte; optionally NaOH to obtain the appropriate pH; and an aqueous solvent.

An electrolyte for electrochemical machining of a γ-γ′ nickel-based superalloy includes NaNO.sub.3 at a content of between 10 and 50% by weight relative to the total weight of the electrolyte; an additive chosen from KBr, NaBr, KI, NaI and mixtures thereof, in an additive/NaNO.sub.3 molar ratio of between 1 and 15; optionally an ethylenediaminetetraacetic acid-based complexing agent at a content of between 1 and 5% by weight relative to the total weight of the electrolyte at a pH of between 6 and 12; optionally an anionic surfactant at a content of between 1 and 5% by weight relative to the total weight of the electrolyte; optionally NaOH to obtain the appropriate pH; and an aqueous solvent.

An electrolyte for the electrochemical machining of a γ-γ″ nickel-based superalloy, includes NaNO3 in a content of between 10% and 30% by weight relative to the total weight of the electrolyte; a complexing agent selected from sulfosalicylic acid at a pH of between 3 and 10 and nitrilotriacetic acid at a pH of between 7 and 14, the complexing agent being present in a content of between 1% and 5% by weight relative to the total weight of the electrolyte; optionally, an anionic surfactant in a content of between 1% and 5% by weight relative to the total weight of the electrolyte; optionally, NaOH in order to obtain the desired pH; and an aqueous solvent.

An electrolyte for the electrochemical machining of a γ-γ″ nickel-based superalloy, includes NaNO3 in a content of between 10% and 30% by weight relative to the total weight of the electrolyte; a complexing agent selected from sulfosalicylic acid at a pH of between 3 and 10 and nitrilotriacetic acid at a pH of between 7 and 14, the complexing agent being present in a content of between 1% and 5% by weight relative to the total weight of the electrolyte; optionally, an anionic surfactant in a content of between 1% and 5% by weight relative to the total weight of the electrolyte; optionally, NaOH in order to obtain the desired pH; and an aqueous solvent.

A method for microengineering a gradient structure on a metal surface. A metal surface including at least first, second, and third metal surface regions is exposed to a metal-removing agent. A portion of surface metal atoms is removed by the metal-removing agent in each of the first, second, and third metal surface regions. Sequential metal removal processes expose only the second and third regions to the metal-removing agent, followed by exposing only the third region to the metal-removing agent. A gradient metal surface is formed having different properties in each of the first, second, and third metal surface regions. In a further aspect, quantitative surface-enhanced Raman spectroscopy may be performed using the treated metal surface. An amount of an analyte is determined based on its position in one of the first, second, or third metal surface regions.

A method for microengineering a gradient structure on a metal surface. A metal surface including at least first, second, and third metal surface regions is exposed to a metal-removing agent. A portion of surface metal atoms is removed by the metal-removing agent in each of the first, second, and third metal surface regions. Sequential metal removal processes expose only the second and third regions to the metal-removing agent, followed by exposing only the third region to the metal-removing agent. A gradient metal surface is formed having different properties in each of the first, second, and third metal surface regions. In a further aspect, quantitative surface-enhanced Raman spectroscopy may be performed using the treated metal surface. An amount of an analyte is determined based on its position in one of the first, second, or third metal surface regions.

This paper describes an invention involving an electrochemical discharge-enabled micro-grinding process for micro-components of silicon-based materials. The specific machining method is described below. A micro-grinding tool and an auxiliary electrode are respectively connected to the negative and positive electrodes of a pulsed DC power supply. When the current flows through the loop, an electrochemical hydrogen evolution reaction (HER) occurs at the micro-grinding tool in the grinding fluid, which generate multiple hydrogen bubbles. The bubbles coalesce into an insulating gas film and separate the micro-grinding tool from the grinding fluid; when the critical voltage is reached, the gas film is broken down and an electrochemical discharge occurs accompanied by discharge spark; under the action of the discharge spark, the surface material of the workpiece in the discharge-affected region is directly ablated to generate a heat-affected layer (HAL), namely, physical modification.

This paper describes an invention involving an electrochemical discharge-enabled micro-grinding process for micro-components of silicon-based materials. The specific machining method is described below. A micro-grinding tool and an auxiliary electrode are respectively connected to the negative and positive electrodes of a pulsed DC power supply. When the current flows through the loop, an electrochemical hydrogen evolution reaction (HER) occurs at the micro-grinding tool in the grinding fluid, which generate multiple hydrogen bubbles. The bubbles coalesce into an insulating gas film and separate the micro-grinding tool from the grinding fluid; when the critical voltage is reached, the gas film is broken down and an electrochemical discharge occurs accompanied by discharge spark; under the action of the discharge spark, the surface material of the workpiece in the discharge-affected region is directly ablated to generate a heat-affected layer (HAL), namely, physical modification.

An electroerosion machining system for trepanning and drilling operations is disclosed. The electroerosion machining system includes an electrode assembly configured to machine a desired configuration in a workpiece, a power supply configured to energize the electrode assembly and the workpiece to opposite electrical polarities, an electrolyte supply configured to pass an electrolyte between the electrode assembly and the workpiece, a working apparatus configured to move the electrode assembly relative to the workpiece, and a control system to control the power supply and the working apparatus. The electrode assembly further includes an electrode body in the form of a tube-shaped body, the tube-shaped body defining a hollow interior and one or more replaceable inserts affixed to the electrode body at a working end thereof positioned adjacent the workpiece, the one or more replaceable inserts constructed so as to be selectively attachable and detachable from the working end of the electrode body.

An electroerosion machining system for trepanning and drilling operations is disclosed. The electroerosion machining system includes an electrode assembly configured to machine a desired configuration in a workpiece, a power supply configured to energize the electrode assembly and the workpiece to opposite electrical polarities, an electrolyte supply configured to pass an electrolyte between the electrode assembly and the workpiece, a working apparatus configured to move the electrode assembly relative to the workpiece, and a control system to control the power supply and the working apparatus. The electrode assembly further includes an electrode body in the form of a tube-shaped body, the tube-shaped body defining a hollow interior and one or more replaceable inserts affixed to the electrode body at a working end thereof positioned adjacent the workpiece, the one or more replaceable inserts constructed so as to be selectively attachable and detachable from the working end of the electrode body.