Vapor Plume Absorption Sensing for Real-Time Laser Process Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in monitoring and adjusting laser processes in real time, particularly in laser-based manufacturing and tissue treatment, due to limited time resolution and inability to accurately assess alloy composition and dynamic plume characteristics.
Innovation Solution
The use of an interrogation laser to direct light toward a vapor plume created during laser-based processes, detecting backscattered light to assess absorption characteristics, temperature, pressure, and composition, and adjusting the energy application accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional optical approaches are used to monitor the vapor plume, then the system is simple, but the time resolution is insufficient to capture dynamic plume and melt pool oscillations
Solution Approach 1:
The patent replaces conventional mechanical/optical monitoring systems with a laser-based diagnostic system. The laser source emits light that interacts with the vapor plume, and detectors measure absorption characteristics to infer plume properties. This substitution enables high time resolution measurements of dynamic plume and melt pool oscillations without the limitations of conventional optical approaches.
2Measurement precision
If on-machine diagnostics are used, then the system is relatively simple, but the capability to predict part quality and provide alloy composition information is limited
Solution Approach 1:
The patent uses the vapor plume itself as an intermediary to obtain information about the melt pool and alloy composition. The laser light passes through the vapor plume, and the absorption characteristics of the plume provide indirect information about the underlying melt pool conditions and material composition. This intermediary approach enables precise measurement of alloy composition and part quality prediction while maintaining relative system simplicity.
3Productivity
If real-time monitoring of the vapor plume is implemented, then process control is improved, but the ability to make proper adjustments during the process is limited by current diagnostic capabilities
Solution Approach 1:
The patent implements a feedback system where laser-based diagnostics continuously monitor the vapor plume absorption characteristics in real-time. The measured absorption data provides information about plume density, temperature, and composition, which feeds back to control the laser processing parameters. This closed-loop feedback enables proper adjustments to be made during the process, improving both productivity and reliability.
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 approach enables real-time monitoring and adjustment of laser processes, improving print quality in 3D printing and laser welding by accurately controlling energy application based on dynamic plume characteristics.
Implementation Method 1
The backscattered light may represent portions of the interrogation laser light that is not absorbed by the vapor plume, either as the light passes through the plume and to the target or from the target toward a detector/sensor, and can thus be used to detect absorption characteristics of the vapor plume
Implementation Method 2
light backscattered therefrom is detected and used to assess the material to which the energy is applied, as well as the effect of the applied energy
Data Source
AI summary
Aspects of the disclosure are directed to assessing characteristics of a target from which a vapor plume is generated. As may be implemented with various embodiments, energy (e.g., laser light, an electron beam) is applied to a target and a vapor plume is created therefrom. An interrogation laser is applied toward the target via the vapor plume, and backscattered light from the interrogation laser is detected. The backscattered light is used to detect absorption characteristics of the vapor plume. Energy is further applied to the target, in which the applied energy is adjusted based on the absorption characteristics. Such approaches facilitate the application of energy to a target for a variety of uses.