Laser Shaping of CMC Sheets for Precise Tolerance Cutting

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Solution Overview

Problem

Conventional mechanical cutting methods for ceramic matrix composite (CMC) sheets result in fiber wear, deformation, and significant variations in shape and size, failing to meet design tolerances due to the application of mechanical force.

Innovation Solution

A laser-based system that receives input signals for predetermined shapes and selects a laser beam to project onto the CMC sheet, cutting or shaping it without mechanical force, using a top-hat beam profile with short pulses to minimize thermal damage and achieve sharp edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a diamond wheel mechanical tool is used to cut the CMC sheet, then the CMC sheet can be cut into predetermined shapes, but mechanical force causes fiber wear out and deformation resulting in large variation in size and shape that does not meet design tolerance

Engineering Contradiction:
Improvecutting capabilityVSAvoidshape and size tolerance
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical diamond wheel cutting system with a laser-based cutting system. The laser beam delivers energy to the CMC sheet material, causing localized heating and ablation without mechanical contact. This substitution eliminates mechanical force application, thereby preventing fiber wear and deformation while achieving precise predetermined shapes that meet design tolerances

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the cutting mechanism from mechanical force to thermal energy. By controlling laser parameters such as power, pulse duration, and scanning speed, the system achieves precise cutting without mechanical contact. The top-hat beam profile with short pulses minimizes thermal damage while maintaining cutting precision, transforming the cutting process from mechanical to thermal-field-based

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional mechanical cutting methods are used, then cutting can be performed, but processing time is long and productivity is low

Engineering Contradiction:
Improvecutting functionVSAvoidprocessing time
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The laser cutting system operates at high speeds without the mechanical constraints of diamond wheel rotation and feed rate limitations. The laser beam can be rapidly positioned and scanned across the CMC sheet, achieving cutting speeds significantly faster than mechanical methods while maintaining precision, thereby reducing processing time and increasing productivity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs pulsed laser operation with short pulses instead of continuous cutting. This periodic energy delivery allows for controlled material removal with minimal heat accumulation, enabling faster processing while preventing thermal damage. The pulsed mode facilitates higher productivity by optimizing the balance between cutting speed and material integrity

Inventive Principle:
Principle #19Periodic action

3Ease of manufacture

If mechanical force is applied to cut the CMC sheet, then cutting can be achieved, but fiber wear out and deformation occur causing undesirable variation

Engineering Contradiction:
Improvecutting capabilityVSAvoidfiber integrity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The laser cutting system eliminates mechanical contact between the cutting tool and CMC sheet. The laser beam delivers energy through electromagnetic radiation, causing localized heating and material ablation without physical force. This preserves fiber integrity by avoiding mechanical stress, wear, and deformation that would otherwise occur with diamond wheel cutting

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The laser cutting process utilizes phase transitions of the CMC sheet material through localized heating. The laser energy causes rapid heating and vaporization of material at the cut line, transitioning from solid to gas phase. This thermal process removes material cleanly without mechanical contact, preserving the integrity of surrounding fibers and avoiding deformation

Inventive Principle:
Principle #36Phase transitions

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

The laser-based system cuts CMC sheets with minimal or zero fiber wear and deformation, maintaining precise shape and size tolerances, and reduces processing time by two to three times compared to conventional methods.

Implementation Method 1

a laser device including a user interface configured to receive an input signal representative of a predetermined shape and a type of the CMC sheet. Further, the laser device includes a processor coupled to the user interface and configured to select a laser beam based on the received input signal. Also, the laser device includes a beam generating unit coupled to the processor and configured to project the selected laser beam on the CMC sheet

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

projecting the selected laser beam on the CMC sheet to shape the CMC sheet into the predetermined shape

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3184230B1System and method for shaping a ceramic matrix composite (CMC) sheet
Publication Date: 2021.04.28 GENERAL ELECTRIC CO
  • EP3184230B1 patent drawingFigure 1
  • EP3184230B1 patent drawingFigure 2~4

AI summary

A method (400) for shaping a ceramic matrix composite (CMC) sheet (206) having a first surface (210) and a second surface (212) is presented. The method includes receiving (402) an input signal representative of a predetermined shape and a type of the CMC sheet. Further, the method includes selecting (404) a laser beam based on the received input signal. Also, the method includes projecting (406) the selected laser beam on the CMC sheet to shape the CMC sheet into the predetermined shape.