Laser Fluence Control for Variable-Speed 3D Scan Processing
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Solution Overview
Problem
Conventional additive manufacturing methods, such as selective laser melting (SLM) and selective laser sintering (SLS), face challenges in achieving rapid production of industrial-grade objects with superior precision and feature resolution, often resulting in inconsistent material properties and reliability issues due to limitations in controlling laser fluence during the processing of targets.
Innovation Solution
The method involves directing a laser beam along a scan path with variable scan velocity and adjusting its digital modulation to maintain fluence within a predetermined range, using a zoom beam expander to vary the spot size and power of the laser beam, and employing a 3D scanning system with a z-axis focus adjust optical system and galvanometer scanning system to ensure precise control over the laser processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional additive manufacturing methods are used, then objects can be manufactured with sequential layers, but the production speed is slow and the finished objects lack reliability and precision detail
Solution Approach 1:
The patent implements dynamic control of laser parameters including variable scan velocity and real-time adjustment of digital modulation based on detected target characteristics. The system continuously adapts laser power, spot size, and scan speed to maintain optimal fluence conditions, enabling both high production speed and reliable finished objects through dynamic process optimization
Solution Approach 2:
The patent systematically varies multiple laser processing parameters including fluence, scan velocity, spot size, and digital modulation frequency. By changing these parameters in real-time based on detected material characteristics, the system achieves both rapid production and high reliability of manufactured objects
2Productivity
If laser scan velocity is increased to improve productivity, then production speed increases, but fluence control becomes inconsistent leading to poor manufacturing precision
Solution Approach 1:
The patent incorporates real-time detection of target characteristics during laser scanning and uses this feedback to dynamically adjust digital modulation and scan velocity. This closed-loop control maintains consistent fluence delivery even at high scan speeds, enabling both rapid production and precise feature resolution
Solution Approach 2:
The patent applies periodic digital modulation to the laser beam at frequencies synchronized with the scan velocity. This periodic action creates consistent thermal cycles in the material that maintain precise melting and fusion characteristics even during high-speed scanning, preserving manufacturing precision while improving productivity
3Productivity
If laser power is increased to improve processing speed, then productivity increases, but melt ejecta generation increases reducing material quality
Solution Approach 1:
The patent applies periodic digital modulation to the laser power at optimized frequencies that create controlled thermal cycles during processing. This periodic action prevents excessive heat accumulation and vapor pressure buildup that lead to melt ejecta, while still maintaining high processing speeds through efficient energy delivery
Solution Approach 2:
The patent dynamically adjusts laser parameters including power, spot size, and scan velocity in real-time to maintain optimal fluence conditions. By changing these parameters based on detected target characteristics, the system achieves high processing speed while preventing the conditions that generate melt ejecta
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 the production of objects with improved material characteristics by maintaining laser fluence within specific thresholds, reducing the generation of melt ejecta and enhancing the precision and reliability of the finished products, thereby overcoming the limitations of conventional additive manufacturing techniques.
Implementation Method 1
directing a laser beam to a target along a scan path
Implementation Method 2
provide a fluence at the target within a predetermined fluence range
Implementation Method 3
adjusting a width of the laser beam with a zoom beam expander so as to provide the laser beam with a variable spot size at the target
Implementation Method 4
a 3D scanning system having a z-axis focus adjust optical system and a galvanometer scanning system
Implementation Method 5
directing a laser beam along a scan path
Implementation Method 6
adjusting a digital modulation during movement of the laser beam along the scan path so as to provide a fluence at the target within a predetermined fluence range
Data Source
AI summary
Methods include directing a laser beam to a target along a scan path at a variable scan velocity and adjusting a digital modulation during movement of the laser beam along the scan path and in relation to the variable scan velocity so as to provide a fluence at the target within a predetermined fluence range along the scan path. Some methods include adjusting a width of the laser beam with a zoom beam expander. Apparatus include a laser source situated to emit a laser beam, a 3D scanner situated to receive the laser beam and to direct the laser beam along a scan path in a scanning plane at the target, and a laser source digital modulator coupled to the laser source so as to produce a fluence at the scanning plane along the scan path that is in a predetermined fluence range as the laser beam scan speed changes along the scan path.