Fluoride Ion Cleaning for Turbine Blade Recast Layer Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ablation machining processes like EDM and laser machining for turbine superalloy components often result in recast layer formation, which complicates the manufacturing process with additional steps, costs, and time delays, especially when chemical etching leaves undesirable oxide films and mechanical methods are inefficient.
Innovation Solution
Incorporating fluoride ion cleaning (FIC) as a subsequent process to easily remove the recast layer formed during ablation machining, allowing for faster and more efficient machining without concerns about recast layer formation, and providing an oxide-free surface for further processing like brazing or welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ablation machining is performed at high speed, then productivity is improved, but recast layer formation increases
Solution Approach 1:
The patent converts the harmful recast layer into a removable byproduct by using fluoride ion cleaning to selectively dissolve the recast layer while leaving the base metal intact. This allows high-speed ablation machining to proceed without concern for recast layer formation, as the layer is easily removed in a subsequent cleaning step, thus transforming the harmful effect into a manageable process step.
2Ease of manufacture
If conventional chemical etching is used to remove recast layer, then recast layer removal is achieved, but oxide films remain on the surface
Solution Approach 1:
The patent changes the chemical parameters of the cleaning process by using fluoride ions specifically targeted at removing oxides and recast layer materials containing oxygen. The fluoride ion cleaning process uses controlled chemical reactions to selectively remove oxide films that conventional etching would leave behind, achieving a cleaner surface suitable for subsequent brazing or welding operations.
3Ease of manufacture
If conventional machining is used to remove recast layer, then recast layer removal is achieved, but surface contaminants are left and additional cleaning is required
Solution Approach 1:
The patent replaces mechanical recast layer removal methods (such as grinding or abrasive blasting) with a chemical dissolution process using fluoride ions. This substitution eliminates the mechanical generation of surface contaminants while effectively removing the recast layer, providing a cleaner surface without requiring additional cleaning steps.
4Object-generated harmful factors
If ablation rate is lowered to minimize recast layer, then recast layer formation is reduced, but production rate decreases
Solution Approach 1:
The patent segments the machining process into two distinct stages: a high-speed ablation machining stage that maximizes productivity, followed by a fluoride ion cleaning stage that removes the recast layer. This segmentation allows each process to be optimized independently - the ablation process runs at maximum speed without recast layer concerns, while the cleaning process efficiently removes the layer, achieving both high productivity and minimal recast layer impact.
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
FIC enables quicker and more efficient ablation machining by simplifying recast layer removal, optimizing machining speed and efficiency, and ensuring a clean surface for subsequent processing steps, reducing the need for additional cleaning and minimizing recast layer-related concerns.
Implementation Method 1
removing the recast layer from the work piece by fluoride ion cleaning
Implementation Method 2
forming a work piece surface to a desired component shape and dimensions by ablation machining
Implementation Method 3
Exemplary ablation machining methods include laser machining and electric discharge machining (EDM)
Data Source
AI summary
Components, such as turbine blades or vanes, are formed to a desired shape and dimensions by ablation machining a work piece surface. Recast layer material created on the work piece surface during the ablation machining is subsequently removed by fluoride ion cleaning (FIC). Exemplary ablation machining methods include laser machining and electric discharge machining (EDM). The work piece material may include superalloys commonly used for fabrication of turbine blades or vanes, which are susceptible to recast layer formation during EDM or laser machining. Post ablation FIC recast layer removal is easier than known methods, such as mechanical grinding, secondary EDM machining of the layer at lower speeds and/or current intensity, or chemical etching processes. Ablation machining processes can be optimized for speed and efficiency without regard for recast layer avoidance, with knowledge that the recast layer will be subsequently removed by the complimentary FIC process.