Laser Ablation Coating Removal with Real-Time LIBS Feedback
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Solution Overview
Problem
Current laser ablation coating removal processes for turbomachine components, such as thermal barrier coatings, rely on empirical methods and manual inspection, leading to inefficiencies and high costs due to the need for tedious rework and potential sublayer damage, especially in areas with tight tolerances and varying coating thickness.
Innovation Solution
Integration of laser-induced breakdown spectroscopy (LIBS) into the laser ablation process to provide real-time compositional feedback, allowing for the optimization of laser parameters and precise control of the ablation process, thereby ensuring complete removal of desired coating layers without damaging underlying layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser ablation is used for coating removal with multiple passes, then coating material can be removed, but the number of passes required is determined empirically by trial and error and manual inspection is needed
Solution Approach 1:
The system incorporates real-time feedback by using LIBS to monitor the chemical composition of the coating during laser ablation. The spectral data provides continuous information about the coating thickness and material composition, allowing the laser processing parameters to be adjusted dynamically to achieve precise coating removal without manual inspection
Solution Approach 2:
The patent replaces the mechanical/manual inspection process with an optical spectroscopy-based detection system. LIBS uses laser-induced plasma emission to non-contactly measure coating composition and thickness in real-time, eliminating the need for physical gauges and manual inspection
2Productivity
If laser ablation is used to remove coating, then coating can be removed, but there is risk of damaging sub layers due to tight tolerances and varying coating thickness
Solution Approach 1:
Real-time spectral feedback from LIBS monitoring allows the system to detect when the coating has been sufficiently removed by identifying changes in the chemical composition signal. This enables precise control of the ablation process to stop before damaging the underlying substrate, maintaining reliability while ensuring complete coating removal
Solution Approach 2:
The system dynamically adjusts laser processing parameters based on real-time spectral data. When the coating thickness varies or tight tolerances are approached, the laser power, pulse duration, or scan speed can be modified to maintain safe ablation rates and prevent sublayer damage
3Manufacturing precision
If manual inspection and rework are performed to ensure complete coating removal, then coating removal accuracy can be improved, but manufacturing cost increases
Solution Approach 1:
The LIBS monitoring system enables the laser ablation process to be self-monitoring and self-regulating. The real-time spectral feedback allows the process to automatically detect coating removal completion and adjust parameters accordingly, eliminating the need for separate manual inspection and rework operations
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
Enables real-time monitoring and control of the coating removal process, reducing manual inspection, minimizing rework, and ensuring accurate removal of coating layers regardless of coating thickness variations, thus improving manufacturing efficiency and reducing costs.
Implementation Method 1
LIBS entails projecting a pulsed laser beam onto a material at a power density sufficient to vaporize (ablate) a small portion of the material and generate a luminous plasma that contains the characteristic atomic emission lines of elements within the material
Implementation Method 2
laser ablation may be utilized for coating removal by rapidly scanning a laser beam across a coated surface
Data Source
AI summary
A system and method for performing laser induced breakdown spectroscopy during laser ablation of a coating, such as a TBC coating, deposited on a surface of a component, particularly to enable obtained spectrometry signals of the ablated coating to be used to monitor and control the laser ablation removal process in real-time. The system includes a laser energy source and a scan head interconnected with the laser energy source to receive a laser beam therefrom and then direct the laser beam onto the surface of the coated component. Collection optics collect radiation emitted from a laser-induced plasma generated by the laser beam at the surface of the coated component. The system is further equipped to spectrally analyze the radiation and generate a feedback signal for control and optimization of one or more operational parameters of the laser energy source in real-time.