Additive Manufacturing Beam Control via Optical Modulator

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Solution Overview

Problem

Existing additive manufacturing methods face challenges in achieving minimal obtainable wall thickness and uniformity of consolidated build material, particularly with multiple passes of energy beams, and are prone to tracking errors due to miscalibration and laser drift.

Innovation Solution

The use of a first device for rapid, small-scale modification of the energy beam trajectory and a second device for slower, larger-scale translational movement, allowing for selective deviations from the nominal beam path to correct tracking errors and create a larger melt pool through beam wobbling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple passes of energy beams are used to achieve minimal wall thickness, then manufacturing precision is improved, but reliability deteriorates due to tracking errors and laser drift

Engineering Contradiction:
Improvewall thicknessVSAvoidtracking accuracy
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The system continuously monitors the actual beam position and compares it to the intended trajectory, then dynamically adjusts the beam path to compensate for deviations. This closed-loop feedback mechanism corrects tracking errors in real-time, maintaining both precision and reliability during multi-pass manufacturing operations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes beam parameters including position, angle, and trajectory during the manufacturing process. By adjusting these parameters in response to detected drift or error, the system maintains accurate wall thickness control while compensating for laser instability over time.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If traditional single-device beam translation is used, then device complexity is reduced, but manufacturing precision deteriorates due to inability to correct tracking errors

Engineering Contradiction:
Improvebeam control systemVSAvoidbeam path accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The beam control system is divided into multiple independent devices, each responsible for specific functions: one device handles coarse beam positioning while another handles fine trajectory adjustments. This segmentation allows each component to be optimized for its specific task, improving overall precision without requiring a single overly complex device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary control system is introduced that sits between the beam source and the workpiece, actively mediating the beam trajectory. This intermediary device detects deviations and applies corrective adjustments, serving as a buffer that maintains precision even when other system components drift or malfunction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If faster beam adjustment is implemented, then productivity is improved, but manufacturing precision may worsen due to reduced control accuracy

Engineering Contradiction:
Improveprocessing speedVSAvoidbeam position control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The control system is segmented into fast-response components for rapid positioning and high-precision components for accurate placement. This allows the system to move the beam quickly across the workpiece while maintaining precise control at each destination point, achieving both high productivity and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses periodic monitoring and adjustment cycles, where beam position is continuously tracked at high speed and corrections are applied at optimized intervals. This periodic feedback approach maintains precision without requiring constant micro-adjustments that would slow down the overall process.

Inventive Principle:
Principle #19Periodic 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 enables improved build characteristics, such as increased wall thickness and reduced errors, by allowing for faster and more precise adjustments to the energy beam path, enhancing the uniformity and accuracy of the additive manufacturing process.

Implementation Method 1

an optical modulator downstream from the beam generating device, the optical modulator configured to modify a position of the energy beam from the nominal beam path trajectory

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

an optical scanner downstream from the optical modulator, the optical scanner configured to translate the energy beam along a build plane of an additive manufacturing machine

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

one or more energy beams are directed onto a powder bed to melt, fuse, or sinter sequential layers of build material such as powder material

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP4353385A1Additive manufacturing methods and systems
Publication Date: 2024.04.17 GENERAL ELECTRIC CO
  • EP4353385A1 patent drawingFigure 1A
  • EP4353385A1 patent drawingFigure 1B
  • EP4353385A1 patent drawingFigure 2A

AI summary

Additive manufacturing methods and systems are disclosed including irradiation devices for an additive manufacturing machine for additively manufacturing three-dimensional objects. The irradiation device includes a beam generation device configured to provide an energy beam travelling on a nominal beam path trajectory and an optical modulator comprising a reflective optic downstream from the beam generating device, wherein the optical modulator is configured to actuate the reflective optic to modify a position of the energy beam from the nominal beam path trajectory. The irradiation device further includes an optical scanner disposed downstream from the optical modulator, wherein the optical scanner is configured to translate the nominal beam path trajectory along a build plane of the additive manufacturing machine.