Silicone-Core Composite Panel for Pore-Free Fusion Welding

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Solution Overview

Problem

Existing structure-borne sound-damping composite materials with metallic and viscoelastic layers face issues with thermal decomposition and gas formation during fusion welding or hot soldering, leading to pore formation and incomplete solidification due to temperatures above 250°C.

Innovation Solution

A component comprising two metallic cover layers and a silicone-containing core layer with dispersed deoxidative elements or alloys, which binds oxygen and prevents pore formation by forming silicon dioxide, allowing for pore-free solidification during fusion welding or hot soldering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fusion welding or hot soldering is applied to composite materials with viscoelastic core layers, then metallic cover layers can be joined, but thermal decomposition occurs and gases are formed causing pores and incomplete solidification

Engineering Contradiction:
Improvejoint strengthVSAvoidsolidification quality
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent converts the harmful effect of oxygen (which causes porosity through gas formation during welding) into a beneficial effect by adding silicon to the core layer. The silicon reacts with oxygen to form silicon dioxide, which binds the oxygen harmlessly and prevents pore formation, thus converting the harmful oxidation process into a protective deoxidation mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical composition parameter of the core layer by adding silicon content specifically controlled between 2-10% by weight. This parameter change enables the core layer material to undergo beneficial chemical reactions during welding, transforming it from a passive viscoelastic layer into an active deoxidizing medium that improves weld quality.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If ferrosilicon powder is added to the plastic core layer to improve resistance welding suitability, then welding performance improves, but fusion welding cannot be used due to thermal decomposition and gas formation at temperatures above 250°C

Engineering Contradiction:
Improvewelding suitabilityVSAvoidwelding method compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent optimizes the silicon content parameter to a higher range (2-10% by weight) compared to conventional ferrosilicon additions, and specifically controls the grain size to be 0.6-1.4 times the core layer thickness. These parameter changes enable the material to withstand fusion welding temperatures while maintaining deoxidation effectiveness, thus expanding welding method compatibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite core layer material combining viscoelastic polymer matrix with dispersed silicon particles of controlled size and distribution. This composite structure allows the material to exhibit both the viscoelastic properties needed for sound damping and the high-temperature stability required for fusion welding, achieving multi-functionality.

Inventive Principle:
Principle #40Composite materials

3Reliability

If silicon is added to the core layer to reduce outgassing during welding, then pore formation decreases, but oxygen binding capacity must be optimized to ensure pore-free solidification

Engineering Contradiction:
Improvesolidification qualityVSAvoidsilicon content
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent precisely optimizes the silicon content parameter within the range of 2-10% by weight of the core layer. This controlled parameter range ensures sufficient oxygen binding capacity to prevent porosity while avoiding excessive silicon addition that would create other problems, thus achieving optimal solidification quality with controlled material quantity.

Inventive Principle:
Principle #35Parameter changes

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 solution enables pore-free solidification and improved adhesion between metallic layers, enhancing the structural integrity and noise-damping properties of the composite material for applications in industries like shipbuilding and aerospace, where hot soldering or fusion welding is necessary.

Implementation Method 1

the silicon in the silicon-containing material decomposes into silicon dioxide in an oxygen-containing atmosphere because of its high affinity for oxygen. The reaction of the silicon with the oxygen significantly reduces the outgassing of the molten metal and the formation of pores

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

deoxidative elements and/or deoxidative alloys, which are dispersed in the silicone-containing core layer in a proportion of between 0.1 and at most 5% by weight, based on the core layer

Methodology Applied
Scientific EffectDeoxidation: Redox Reactions

Data Source

PatentEP3143304B1Construction element
Publication Date: 2022.07.06 THYSSENKRUPP AG

AI summary

The invention relates to a construction element consisting of two metallic covering layers and a non-metallic core layer arranged between the covering layers. The problem addressed by the invention is that of proposing a construction element that is suitable for fusion-welding and/or hot soldering. This problem is solved for a construction element having the features of the main claim.