Multilayer Metal Tube Diffusion Bonding via Nested Block Compression

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Solution Overview

Problem

Existing methods for manufacturing multilayer metal pipes often result in incomplete contact between layers, leading to discontinuous physical properties and high production costs due to the use of long, thin tubes with small wall thicknesses, which are expensive to process and connect.

Innovation Solution

A method involving the nesting of inner and outer hollow blocks, which are heated and reduced in wall thickness using a push bench process, allowing for a diffusion connection between layers without the need for additional heat treatment, using blocks as starting materials to simplify the process and achieve continuous property transition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If welding or soldering is used to connect tube ends, then the tubes can be joined together, but the connection is discontinuous and physical properties are not continuously transitioned

Engineering Contradiction:
Improveconnection strengthVSAvoidcontinuity of physical properties
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent changes the connection method from discrete welding/soldering to continuous diffusion bonding by controlling temperature and pressure parameters during the joining process, enabling continuous physical property transition across the joint

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical connection method (welding/soldering) with a thermal-diffusion process where atoms interdiffuse across the interface, creating a continuous metallurgical bond without discrete connection points

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

2Shape

If long tubes with small wall thickness are used as starting materials, then the multilayer structure can be formed, but production costs increase and processing becomes difficult

Engineering Contradiction:
Improvemultilayer tube structureVSAvoidproduction cost and processing ease
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent performs preliminary forming of the multilayer structure by nesting blocks before final tube drawing, avoiding the need to handle and process long thin-walled tubes at intermediate stages

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent inverts the conventional sequence by starting with solid or hollow blocks instead of thin-walled tubes, forming the multilayer structure in a stable configuration before final tube formation

Inventive Principle:
Principle #13The other way round (Inversion)

3Strength

If discrete welding or soldering points are used to connect tubes, then the tubes can be joined, but adhesion between layers is insufficient

Engineering Contradiction:
Improvelayer adhesionVSAvoidconnection method complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the joining operation with the forming operation by performing diffusion bonding during the tube drawing process, eliminating the need for separate welding or soldering steps

Inventive Principle:
Principle #5Merging (Combining)

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 method produces multilayer metal pipes with a seamless diffusion connection between layers, ensuring continuous physical property transition and improved adhesion, reducing production complexity and costs, and allowing for ultrasonic inspection without flaws.

Implementation Method 1

allowing for a diffusion connection between layers

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

reducing the wall thickness of the nested blocks by treatment on a push bench

Methodology Applied
Scientific EffectPlasticity: Plasticity

Data Source

PatentEP2602032B1Method for producing a multilayer metal tube
Publication Date: 2019.06.05 BENTELER STEEL TUBE GMBH & CO KG
  • EP2602032B1 patent drawingFigure 1a~1b
  • EP2602032B1 patent drawingFigure 2a~2c
  • EP2602032B1 patent drawingFigure 3a~3b

AI summary

The method involves interlocking the inner blocks (10,16) and the outer hollow blocks (11), and heating the mutually inserted blocks. The wall thickness of the inner blocks inserted into outer blocks, is reduced by the treatment on a push bench so as to form a multilayer metal tube (1). An independent claim is included for multilayer metallic tube.