Conductive Protective Layer for Electrochemical Machining Precision
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Solution Overview
Problem
Existing electrochemical machining methods for gas turbine and compressor components often result in undesirable geometry changes and exceeded drawing tolerances due to unintended removal of already finished workpiece surfaces, hindering automation in engine manufacturing.
Innovation Solution
Applying an electrically conductive layer with similar electrochemical removal behavior to the workpiece material on already finished surfaces, which is completely or almost completely removed during the machining process, ensuring protection and precise machining without influencing adjacent areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If electrochemical machining process is applied to remove material from workpiece surface, then machining precision is improved, but already finished workpiece surfaces are attacked and partially removed leading to geometry changes
Solution Approach 1:
An electrically conductive layer is applied as an intermediary between the electrochemical machining process and the workpiece surface. This layer acts as a sacrificial mediator that undergoes electrochemical removal instead of the workpiece material, thereby protecting the finished surfaces from unwanted material removal while allowing the machining process to proceed with high precision.
Solution Approach 2:
The electrically conductive layer is applied in advance to the areas adjacent to the machining surface before the electrochemical machining process begins. This preliminary action ensures that the protective layer is in place to prevent stray currents from attacking the finished workpiece surfaces during the subsequent machining operation.
2Shape
If protective layers are applied to protect finished surfaces, then workpiece geometry is preserved, but the protective layers are partially attacked and require selective removal
Solution Approach 1:
The electrically conductive layer is designed to have similar or identical electrochemical removal behavior to the workpiece material. This homogeneity in electrochemical properties ensures that the protective layer is removed under the same conditions as the workpiece material during electrochemical machining, eliminating the need for separate selective removal steps and simplifying the overall manufacturing process.
Solution Approach 2:
The electrically conductive layer is designed as a sacrificial protective layer that is completely or almost completely removed during the electrochemical machining process. This approach follows the principle of discarding a temporary protective element that serves its purpose during machining and is then naturally removed, eliminating the need for additional selective removal operations.
3Productivity
If conventional electrochemical sinking is used, then material removal is achieved, but drawing tolerances are exceeded due to unwanted material removal
Solution Approach 1:
The electrically conductive layer serves as a mediator that absorbs the electrochemical attack intended for the workpiece. By placing this layer between the electrolyte and the finished workpiece surfaces, the process maintains high material removal efficiency while preventing tolerance violations on protected surfaces.
Solution Approach 2:
The electrically conductive layer is applied selectively only to the areas adjacent to the machining surface that require protection, while leaving the machining surface itself exposed. This local application ensures that protection is provided exactly where needed without interfering with the machining process, maintaining both productivity and precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for precise machining of workpieces without further removal of already finished surfaces, maintaining geometry accuracy and enabling seamless transitions, thus preventing tolerance issues and facilitating automation in engine component production and repair.
Implementation Method 1
material is removed from the workpiece through an electrochemical reaction between the workpiece and the electrolyte located between the workpiece and the electrode
Implementation Method 2
The layer according to process step a) is applied by painting or by a thermal spraying process. The thermal spraying process can be arc spraying, flame spraying, atmospheric plasma spraying, or high-speed flame spraying using VPS
Data Source
Figure 1~2
Figure 3
AI summary
The method involves applying an electrically conductive protective layer on an area of a finished partial component surface (12) abutting a working surface (14) to be processed, where the protective layer includes a metal, and another electrically conductive material having an electrochemical erosion behavior with a known relation to an electrochemical erosion behavior of a metal component. The working surface and the protective layer are electrochemically processed, where the protective layer is completely eroded in a predetermined region. The electrochemical process is pulsed electrochemical sinking process, non-pulsed electrochemical sinking process or drilling process. The protective layer has a thickness range of about 1 micrometer (mue m) to 2 millimeters (mm). Independent claims are also included for the following: (1) a process for manufacturing and repairing a metal component of a rotating machine (2) a component of a rotating machine has a section repaired by joining.