3D Shaping Defect Prevention via Reflection Intensity Feedback

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Solution Overview

Problem

Current three-dimensional shaping methods using laser or electron beam sintering often result in sintering defects due to irregular beam control and powder layer formation, leading to non-flat surfaces and incomplete melting, which are only detected after completion of lamination and sintering steps.

Innovation Solution

A method that involves measuring the reflection intensity of the laser or electron beam during each sintering step, canceling sintering if defects are detected, and using spectral imaging to differentiate between beam control and powder layer issues, allowing for real-time defect detection and prevention of further lamination and sintering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If laser beam or electron beam control is performed during sintering, then the powder layer can be sintered to form a three-dimensional shaped body, but control system problems may result in excess or insufficiency of beam supply, creating non-flat sintering surfaces with regular uneven conditions

Engineering Contradiction:
Improvesintering processVSAvoidsintering surface flatness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism by measuring the reflection intensity of the laser beam or electron beam during sintering. The system continuously monitors the sintering surface condition through reflection intensity measurements and compares them against standard ranges. When deviations are detected, the system provides feedback to adjust the sintering process, ensuring surface flatness and preventing defects while maintaining manufacturing efficiency.

Inventive Principle:
Principle #23Feedback

2Productivity

If powder layer formation is performed by powder supply apparatus, then the powder layer can be supplied for sintering, but uneven conditions or chip infiltration may hamper squeegee movement, making it difficult to achieve uniform flat surfaces

Engineering Contradiction:
Improvepowder layer formationVSAvoidpowder layer surface uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by measuring the reflection intensity of the laser beam or electron beam during the sintering process to detect potential defects before they propagate. By detecting irregularities in the powder layer surface or incomplete melting early in the sintering step, the system can take corrective action before subsequent lamination steps amplify the defects, thereby maintaining surface uniformity without compromising productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors sintering quality through reflection intensity measurements and provides real-time feedback. When non-flat conditions or incomplete melting are detected, the feedback mechanism allows for immediate process adjustment, preventing defect accumulation and ensuring uniform powder layer surfaces for subsequent manufacturing steps.

Inventive Principle:
Principle #23Feedback

3Ease of manufacture

If lamination and sintering steps are repeated in a sealed apparatus, then three-dimensional shaped bodies can be produced, but sintering defects are overlooked until completion of all lamination and sintering steps

Engineering Contradiction:
Improvethree-dimensional shaping processVSAvoiddefect detection time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent implements real-time feedback by measuring the reflection intensity of the laser beam or electron beam during each sintering step. This continuous monitoring provides immediate detection of sintering defects such as non-flat surfaces or incomplete melting, allowing for timely corrective action before the completion of all lamination and sintering steps, thereby eliminating the time loss associated with post-process defect detection.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-service quality control by automatically monitoring its own sintering process through reflection intensity measurements. The apparatus detects and identifies defects during the manufacturing process itself, without requiring external inspection after completion, enabling immediate correction and preventing defective product formation.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If reflection intensity measurement is performed during each sintering step, then sintering defects can be detected rapidly, but the system complexity increases due to additional measurement and control mechanisms

Engineering Contradiction:
Improvesintering defect detectionVSAvoidbeam control and measurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a feedback-based quality control system that measures the reflection intensity of the laser beam or electron beam during sintering. This approach provides precise defect detection by monitoring changes in reflection intensity that indicate sintering abnormalities. The system manages complexity by using the existing beam infrastructure for measurement and implementing automated decision-making algorithms that compare measured values against predetermined standard ranges, enabling precise detection without proportionally increasing overall system complexity.

Inventive Principle:
Principle #23Feedback

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 rapid detection and prevention of sintering defects, preventing the production of defective three-dimensional shaped products and allowing for efficient correction and reprocessing of sintering regions.

Implementation Method 1

sintering step in which the powder layer is sintered by irradiation of a moving laser beam or electron beam

Methodology Applied
Scientific EffectLaser beam irradiation: Laser

Implementation Method 2

sintering step in which the powder layer is sintered by irradiation of a moving laser beam or electron beam

Methodology Applied
Scientific EffectElectron beam irradiation: Electron Beam

Implementation Method 3

sintering step in which the powder layer is sintered by irradiation of a moving laser beam or electron beam

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 4

Measuring the reflection intensity of the laser beam or electron beam irradiated during each sintering step

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3434392B1Three-dimensional shaping method
Publication Date: 2019.09.11 MATSUURA MACHINERY CO LTD
  • EP3434392B1 patent drawingFigure 1(a)~1(b)
  • EP3434392B1 patent drawingFigure 2
  • EP3434392B1 patent drawingFigure 3(a)~3(b)

AI summary

A three-dimensional shaping method that allows defects in three-dimensional shaped products to be avoided by rapidly detecting sintering defects, wherein the sintering step comprises the following operations: a. measuring the reflection intensity of the laser beam or electron beam irradiated in each sintering step, or the reflection intensity of light other than the laser beam, b. commanding to continue sintering within the next time unit, or the next powder layer forming step is given, when it has been detected that the reflection intensity of the process a is within a standard range for a given time unit, and then, c. judging that a sintering defect has been produced, and commanding to cancel sintering in the next time unit, or the next powder layer forming step is given, when it has been detected that a condition has occurred in which the reflection intensity of the process a deviates from the standard range for a given time unit. Further, the cause of the sintering defect is determined as the control system of the beam or the powder layer surface, based on the speed of change of a spectral image or reflection intensities.