Adaptive Shielding Gas Flow for Laser Processing Quality

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Solution Overview

Problem

Laser-based material processing methods, such as selective laser melting and laser welding, face issues with inhomogeneous material structures and poor quality due to fume and vapor interaction with the laser beam, leading to attenuated beam quality and contamination of the process chamber, which increases production costs and time.

Innovation Solution

The method involves controlling the shielding gas flow intensity and direction to prevent fumes and vapors from interacting with the laser beam by maintaining an angle of at least 45 degrees between the shielding gas flow vector and the advance vector, ensuring that fumes are blown over solidified material and not influencing the processing cycle, thereby maintaining process quality and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If shielding gas flow rate is increased to purge fumes, then chamber contamination is reduced, but processing time increases and production efficiency decreases

Engineering Contradiction:
Improvechamber contaminationVSAvoidproduction efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The shielding gas flow rate is dynamically adjusted based on real-time monitoring of fume generation. The control system varies the gas flow intensity according to the actual processing conditions, material type, laser power, and fume detection levels, rather than maintaining a constant high flow rate. This dynamic adjustment resolves the contradiction by providing adequate purging only when and where needed, reducing unnecessary gas consumption and processing time while maintaining chamber cleanliness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates sensors that continuously monitor fume concentration and laser beam attenuation in the processing chamber. This feedback information is fed to the control system, which automatically adjusts the shielding gas flow rate to maintain optimal processing conditions. The feedback mechanism ensures that gas flow is increased only when fume levels threaten to interfere with the laser beam, rather than running at maximum capacity continuously, thus resolving the contradiction between effective purging and production efficiency.

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If shielding gas flow intensity is increased to prevent fume interaction with laser beam, then beam attenuation is reduced, but processing quality deteriorates due to inhomogeneous material structures

Engineering Contradiction:
Improvebeam attenuationVSAvoidmaterial structure homogeneity
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system applies shielding gas flow locally and selectively rather than uniformly across the entire processing area. The control system directs gas flow specifically to regions where fume generation is detected and where laser beam attenuation is occurring, while maintaining different flow conditions in other areas. This local quality approach prevents beam attenuation in critical zones without creating the inhomogeneous material structures that would result from uniform high-intensity gas flow across the entire processing area.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically changes the shielding gas flow parameters (rate, direction, distribution) based on real-time processing conditions. By adjusting these parameters in response to monitored fume levels and beam attenuation, the system maintains optimal gas flow intensity that prevents beam interference while avoiding excessive flow that would cause material structure inhomogeneity. The parameter changes are coordinated with laser power and processing speed to maintain consistent material quality.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If processing trajectory is restricted to avoid fume interaction zones, then process quality is maintained, but chamber utilization decreases and production time increases

Engineering Contradiction:
Improveprocess qualityVSAvoidchamber utilization
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system dynamically adjusts the processing trajectory and shielding gas flow coordination in real-time. Rather than restricting the laser to fixed safe zones, the control system continuously monitors fume generation and beam attenuation, then dynamically modifies both the gas flow parameters and trajectory execution to maintain quality throughout the entire chamber. This allows the laser to access previously restricted areas while maintaining process quality through active fume management rather than spatial restrictions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system maintains continuous useful action by coordinating shielding gas flow with the entire processing trajectory without interruptions or restrictions. The gas flow system operates continuously to manage fumes across all processing zones, allowing the laser to maintain optimal power and speed throughout the full chamber volume. This eliminates the need to pause or redirect the laser to avoid fume zones, maintaining continuous productive operation while preserving process quality through active fume control.

Inventive Principle:
Principle #20Continuity of useful action

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 enhances the quality of processed materials by minimizing beam attenuation and chamber contamination, increasing production efficiency and flexibility, while maintaining high process quality and reducing production costs.

Implementation Method 1

a flow of shielding gas is used to purge the fumes

Methodology Applied
Scientific EffectGas flow: Convection

Implementation Method 2

a high intensity laser beam is directed onto a material, in particular a metal, in order to melt the material

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP3050666B2Method of processing materials by applying a laser beam with adaptive shielding gas flow
Publication Date: 2022.08.10 GENERAL ELECTRIC TECH GMBH
  • EP3050666B2 patent drawingFigure 1~2
  • EP3050666B2 patent drawingFigure 3a~3b
  • EP3050666B2 patent drawingFigure 4

AI summary

A method of material processing is disclosed, the method comprising applying a laser beam (5), directing the laser beam (5) to a processing location (6) to melt material (3) at the processing location (6), and providing a shielding gas flow (8). The shielding gas flow (8) is controlled dependent on at least one of a processing location (6) position, a processing advance vector, and a processing trajectory.