Sealed Cavity Structure Assembly to Prevent Diffusion Welding Deformation

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Solution Overview

Problem

Existing methods for manufacturing structures with hollow parts face challenges in achieving complex geometries, dimensional and geometric tolerances, and preventing deformation during assembly, particularly in diffusion welding processes.

Innovation Solution

A method involving forming hollow areas in a substrate, depositing a plate on the substrate, performing vacuum-through welding around the hollow areas to seal the perimeter, and followed by hot isostatic compression diffusion welding to form sealed cavities, using materials like copper, titanium, aluminum, steel, or vanadium alloys.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If diffusion welding is used to assemble hollow parts, then assembly strength and sealability are improved, but deformation of hollow sections occurs during the process

Engineering Contradiction:
Improveassembly strengthVSAvoidhollow section deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The hollow sections are pre-assembled into the complete structure before the diffusion welding process. This preliminary assembly allows the hollow sections to maintain their shape through mechanical support during subsequent welding operations, preventing deformation that would occur if welding were performed on loose sections.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Support structures and fixtures are prepared in advance to cushion and restrain the hollow sections during diffusion welding. These pre-positioned supports prevent collapse and deformation by providing mechanical counterforce against the compressive loads applied during the welding process.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Shape

If additive manufacturing is used to create hollow parts, then complex geometries are achieved, but dimensional and geometric tolerances are not met

Engineering Contradiction:
Improvecomplex geometryVSAvoiddimensional tolerance
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The structure is divided into separate components: a substrate with formed hollow sections and a distinct plate component. The hollow sections are created using traditional forming methods that achieve better tolerances, while the plate is separately manufactured and then joined via diffusion welding. This segmentation allows each component to be optimized independently for its specific requirements.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If material removal machining is used to form channels, then simple geometries are achieved, but complex channel geometries cannot be obtained

Engineering Contradiction:
Improvegeometric accuracyVSAvoidchannel geometry flexibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

Different manufacturing methods are applied to different parts of the structure. The substrate is formed using techniques suitable for creating complex hollow geometries, while the plate is manufactured with high precision for sealing surfaces. This local application of appropriate manufacturing methods allows the structure to achieve both complex geometries and high precision where needed.

Inventive Principle:
Principle #3Local quality

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

Enables the production of structures with complex shaped cavities, avoiding deformation and misalignment, while ensuring a uniform weld with reduced residual stresses and lower costs, suitable for heat exchangers.

Implementation Method 1

perform vacuum-through welding around the hollow areas, thereby welding the plate onto the substrate

Methodology Applied
Scientific EffectVacuum transparency welding: Laser Beam Welding

Implementation Method 2

carry out a hot isostatic compression diffusion welding step on the assembly obtained

Methodology Applied
Scientific EffectHot isostatic compression diffusion welding: Diffusion Welding

Data Source

PatentEP4438215B1Method for manufacturing a structure comprising cavities, and corresponding structure
Publication Date: 2025.12.24 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4438215B1 patent drawingFigure 1~4A
  • EP4438215B1 patent drawingFigure 4B~4D
  • EP4438215B1 patent drawingFigure 4E~5B

AI summary

This application relates to a method for manufacturing a structure comprising cavities, the method comprising the following steps: a) forming hollow areas (110) in a first face (101) of a substrate (100) made of a first material; b) depositing a plate (200) made of a second material onto the first face (101) of the substrate (100), so as to cover the hollow areas (110) of the substrate (100); c) performing resistance welding, electron beam welding, or laser beam welding, preferably under vacuum, around the hollow areas, thereby welding the plate (200) onto the substrate (100) and forming cavities; and d) performing a hot isostatic compression diffusion welding step on the resulting assembly. This application relates to such a structure.