Transient Liquid Phase Bonding for Metal-Plated Composite Coatings

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Solution Overview

Problem

Conventional methods for joining metal-coated non-metallic materials, such as polymers and composites, are inadequate as they often deform or destroy the polymer or composite substrate due to high temperatures required for welding or brazing, and existing metallic coating application methods fail to provide a robust, thermally stable bond with customized properties.

Innovation Solution

A method involving transient liquid phase (TLP) bonding, where an interlayer composed of elements like gallium, indium, or selenium is used between a metallic component and a metal-plated non-metallic component, heated to a bonding temperature to form a solidified bond, allowing for customized coatings with enhanced properties and a bond that exceeds the bonding temperature's melting point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If welding or brazing is used to join metal components, then strong bonding is achieved, but the polymer or composite substrate deforms or destroys due to high temperatures

Engineering Contradiction:

Improvebond strengthVSAvoidsubstrate deformation or destruction

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

A metal interlayer is introduced as an intermediary between the polymer/composite component and the metal component. This interlayer serves as a mediator that can withstand the bonding temperature while bonding to both the polymer/composite (at lower temperatures) and the metal (at higher temperatures), thereby enabling strong bonding without directly exposing the polymer/composite substrate to high temperatures that would cause deformation or destruction

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The bonding process utilizes temperature parameter changes by heating the bond region to a bonding temperature that melts the interlayer, then maintaining the temperature until the liquid solidifies. This controlled temperature parameter change enables bonding at temperatures below those required for conventional welding or brazing, protecting the polymer/composite substrate from thermal damage

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional coating methods are used, then coating application is simple, but the bond between coating and substrate lacks thermal stability and robustness

Engineering Contradiction:

Improvecoating application simplicityVSAvoidbond thermal stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The bonding process exploits phase transitions by heating the bond region to a bonding temperature that melts the interlayer, creating a liquid phase that enhances bonding. The liquid interlayer then solidifies upon cooling, forming a robust and thermally stable bond between the coating and substrate that exceeds the capabilities of conventional coating methods

Inventive Principle:

Principle #36Phase transitions

3Productivity

If conventional coating methods are used, then coating is applied efficiently, but customized coatings with blended microstructural and physical properties cannot be achieved

Engineering Contradiction:

Improvecoating application efficiencyVSAvoidcoating customization capability

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The process creates a composite structure at the bond region by forming an intermetallic compound layer between the interlayer and the substrate, and a mixture layer between the interlayer and the coating. This composite microstructure combines the properties of the substrate and coating materials, enabling customized coatings with blended microstructural and physical properties while maintaining efficient application through the TLP bonding process

Inventive Principle:

Principle #40Composite materials

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 enables strong, thermally stable bonding of metal-coated non-metallic components without deforming the substrate, providing customized coatings with microstructural and physical properties between those of the substrate and coating, suitable for applications in industries like aerospace and automotive.

Implementation Method 1

heating the bond region to a bonding temperature to produce a liquid at the bond region

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

maintaining the bond region at the bonding temperature until the liquid produced at the bond region has solidified to form a bond

Methodology Applied

Scientific EffectIsothermal solidification: Phase Change

Data Source

PatentEP4371692A1Transient liquid phase bonding of surface coatings and metal-covered materials

Publication Date: 2024.05.22 RTX CORP

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AI summary

A method for bonding components is disclosed. The method may comprise positioning an interlayer between a metallic component and a metal-plated non-metallic component at a bond region, heating the bond region to a bonding temperature to produce a liquid at the bond region, and maintaining the bond region at the bonding temperature until the liquid has solidified to form a bond between the metallic component and the metal-plated non-metallic component at the bond region. A method for providing a part having a customized coating is also disclosed. The method may comprise applying a metallic coating on a surface of a metallic substrate, and bonding the metallic coating to the metallic substrate by a transient liquid phase bonding process to provide the part having the customized coating.