Multi-Wavelength Temperature Sensing for Laser Melt Pool Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In selective laser melting processes, the variation in melt pool dimensions due to different heat dissipation conditions affects the quality of three-dimensional printed products, as the power of the laser beam must be adjusted based on whether the structure is suspended or not, leading to unsatisfactory shapes.
Innovation Solution
A temperature sensing apparatus comprising a lens set, filtering module, and sensor arrays that measure temperature distribution by filtering radiation into different wavelengths and calculating an intensity ratio distribution, allowing for real-time monitoring and adjustment of the laser beam power to maintain stable melt pool conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the laser beam power is maintained the same for both suspended and non-suspended welded structures, then the manufacturing process is simple, but the shape and temperature distribution of the melt pool are unsatisfactory
Solution Approach 1:
The patent employs a temperature sensing apparatus that detects the temperature distribution of the melt pool in real-time during the selective laser melting process. The detected temperature information is fed back to the laser power control system, which dynamically adjusts the laser power based on the actual temperature distribution. This feedback mechanism enables the system to adapt to different heat dissipation conditions of suspended versus non-suspended structures, optimizing the melt pool shape and temperature distribution for each case.
Solution Approach 2:
The patent changes the laser power parameter dynamically based on the detected temperature distribution and the identification of suspended structures. By adjusting the laser power according to the specific thermal conditions and structural context (suspended vs. non-suspended), the system optimizes the melting process to achieve satisfactory melt pool characteristics for both types of structures.
2Manufacturing precision
If the laser beam power is adjusted based on whether the structure is suspended or not, then the melt pool shape is improved, but the manufacturing process complexity increases
Solution Approach 1:
The temperature sensing apparatus provides real-time temperature distribution data that feeds back to the laser power control system. This feedback enables automatic identification of suspended structures and dynamic adjustment of laser power, improving melt pool shape without requiring complex manual intervention or pre-programming for each structure type.
Solution Approach 2:
The patent replaces complex mechanical or manual adjustment mechanisms with an optical-based temperature sensing and control system. By using non-contact temperature measurement and automated feedback control, the system achieves precise laser power adjustment without the complexity of mechanical adjustment devices or manual operations.
3Device complexity
If traditional single-wavelength temperature measurement is used, then the measurement system is simple, but the temperature detecting range is limited
Solution Approach 1:
The patent segments the thermal radiation measurement into multiple wavelength bands using a filtering module with multiple bandpass filters. Each filter captures radiation in a specific wavelength range, and the corresponding sensor arrays detect the intensity in each band. This segmentation of the measurement spectrum enables wide temperature range detection by selecting appropriate wavelength bands for different temperature regions.
Solution Approach 2:
The patent transitions from single-wavelength measurement to multi-wavelength spectral measurement, adding the wavelength dimension to the temperature measurement process. By measuring radiation intensity across multiple wavelengths and analyzing the spectral distribution, the system achieves extended temperature detecting range while maintaining manageable system complexity through modular filter and sensor array design.
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 accurate temperature measurement and control of the melt pool, ensuring consistent shape and structure of three-dimensional objects regardless of suspended or non-suspended welded structures, with a wide temperature detecting range from 100°C to 2500°C.
Implementation Method 1
The lens set is configured to receive radiation from the surface to be measured
Implementation Method 2
The filtering module is configured to filter the radiation from the lens set into a plurality of radiation portions respectively having different wavelengths
Implementation Method 3
The sensor arrays are configured to respectively sense the radiation portions
Data Source
AI summary
A temperature sensing apparatus configured to measure a temperature distribution of a surface to be measured is provided. The temperature sensing apparatus includes a lens set, a filtering module, a plurality of sensor arrays, and a processing unit. The lens set is configured to receive radiation from the surface to be measured. The filtering module is configured to filter the radiation from the lens set into a plurality of radiation portions respectively having different wavelengths. The sensor arrays are configured to respectively sense the radiation portions. The processing unit is configured to calculate an intensity ratio distribution of the radiation between the different wavelengths according to the radiation portions respectively sensed by the sensor arrays and determine the temperature distribution according to the intensity ratio distribution. A laser processing system and a temperature measuring method are also provided.