Laser-Welded Metallic Mesh Patching for In-Situ Machine Repair

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Solution Overview

Problem

Conventional in-situ repair techniques for machines, such as gas turbine engines, face inefficiencies and safety concerns due to high wastage of metallic powders, limitations in size and material efficiency of wire deposition, heat distortion issues with diffractive optic lenses, and unsuitability of composite patches for high-stress environments.

Innovation Solution

A repair system utilizing a laser unit, galvanometer, and a continuous supply of flexible metallic mesh, which is deposited and laser-welded onto the machine surface, allowing for customizable repair patches with reduced wastage and improved efficiency, and optionally using shielding gas and ceramic coatings for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If laser cladding of metallic powder is used for in-situ repair, then repair can be performed on damaged surfaces, but material wastage is high (30-40%) and the process is complicated

Engineering Contradiction:
Improvemetallic powder wastageVSAvoidrepair process complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent changes the physical form of the repair material from powdered metallic powder to continuous metallic wire, fundamentally altering the material delivery parameters. This transformation eliminates the dispersal and collection requirements for powder, reducing material wastage from 30-40% to minimal levels while simplifying the overall repair process configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the complex powder delivery and collection mechanical system with a simpler wire feed mechanism. The wire is fed continuously through a laser beam path using a controlled feed system, eliminating the need for powder hoppers, pneumatic delivery systems, and powder collection apparatus, thereby reducing device complexity

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

2Loss of substance

If laser wire deposition is used for in-situ repair, then material efficiency improves, but the process is limited by wire size and repair speed slows down

Engineering Contradiction:
Improvematerial efficiencyVSAvoidrepair speed
Core Design Contradiction:
Loss of substanceVSProductivity

Solution Approach 1:

The patent segments the repair area into multiple passes or zones that can be treated sequentially with the wire deposition process. By dividing the repair task into manageable sections and using automated positioning, the system maintains material efficiency while improving overall repair throughput through systematic coverage of the damaged area

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements continuous wire feeding during the laser deposition process, eliminating interruptions and maintaining steady-state operation. The wire is fed continuously at a controlled rate that matches the laser scanning speed, ensuring uninterrupted material deposition and maximizing repair productivity while preserving material efficiency

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If laser cladding of strips with diffractive optic lenses is used, then repair can be performed, but large melt pools cause significant heat distortion

Engineering Contradiction:
Improverepair capabilityVSAvoidheat distortion
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies localized heating through a focused laser beam that creates a small, controlled melt pool directly at the repair location. The energy is concentrated in a small area rather than distributed across a large zone, allowing precise control of the melting and deposition process while minimizing thermal affect zones and heat distortion in surrounding areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses a mobile laser system that can dynamically adjust its position, focal point, and scanning speed during the repair process. This dynamic control allows the laser to maintain optimal parameters for each location, adjusting the melt pool size and heat input in real-time to minimize heat distortion while effectively repairing the damaged surface

Inventive Principle:
Principle #15Dynamics

4Ease of repair

If composite patches are used for in-situ repair, then repairs can be applied to cracks and defects, but they are not suitable for high stress conditions

Engineering Contradiction:
Improverepair applicabilityVSAvoidstress resistance
Core Design Contradiction:
Ease of repairVSStrength

Solution Approach 1:

The patent employs composite material structure where a metallic wire coating is deposited over a prepared substrate surface. The wire material is selected to match or exceed the mechanical properties of the base material, creating a composite structure that combines the substrate with the repair material to achieve high strength and stress resistance suitable for demanding applications

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent creates a convex, rounded repair surface through controlled wire deposition and laser melting. This curved geometry distributes stress more evenly across the repair area compared to flat patches, reducing stress concentration points and improving the overall strength and durability of the repair under high stress conditions

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 system provides efficient, customizable, and safer in-situ repair with reduced material wastage, enabling complex repairs on machines like gas turbine engines, improving efficiency and adaptability to various application conditions.

Implementation Method 1

a laser unit configured to emit a laser beam

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

a galvanometer optically coupled to the laser unit and configured to adjust the laser beam received from the laser unit

Methodology Applied
Scientific EffectGalvanometer beam deflection: Galvanometer

Implementation Method 3

The controller is further configured to control the galvanometer to adjust the laser beam in order to weld the flexible metallic mesh to the surface of the machine

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP4309840A1Repair system and method for in-situ repair of machine
Publication Date: 2024.01.24 ROLLS ROYCE PLC
  • EP4309840A1 patent drawingFigure 1
  • EP4309840A1 patent drawingFigure 2
  • EP4309840A1 patent drawingFigure 3

AI summary

A repair system (100) for in-situ repair of a machine (101) is provided. The repair system (100) includes a laser unit (102) configured to emit a laser beam (104), a galvanometer (106) optically coupled to the laser unit (102) and configured to adjust the laser beam (104) received from the laser unit (102), a source (108) of a flexible metallic mesh (110), a delivery unit (112) configured to receive the flexible metallic mesh (110) from the source (108) of the flexible metallic mesh (110), and a controller (114) communicably coupled to the laser unit (102), the galvanometer (106), and the delivery unit (112). The controller (114) is configured to control the delivery unit (112) to deposit the flexible metallic mesh (110) on a surface (124) of the machine (101). The controller (114) is further configured to control the laser unit (102) to emit the laser beam (104). The controller (114) is further configured to control the galvanometer (106) to adjust the laser beam (104) in order to weld the flexible metallic mesh (110) to the surface (124) of the machine (101), thereby forming a repair patch (126).