Metal-Coated Composite Bonding With Low-Temperature TLP Interlayers

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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 fastening methods like bolts and rivets have limitations, while current coating application methods fail to provide a robust and thermally stable bond with customized properties.

Innovation Solution

The use of a transient liquid phase (TLP) bonding process involving an interlayer of elements like gallium, indium, or selenium between a metal-coated non-metallic component and a metallic substrate, which melts and solidifies to form a strong, thermally stable bond, allowing for customized coatings with combined properties of the substrate and coating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If welding or brazing is used to join metal components, then strong bonds are achieved, but polymer or composite substrates deform or destroy due to high temperatures

Engineering Contradiction:

Improvebond strengthVSAvoidthermal damage to polymer substrate

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a low-melting-point interlayer material (such as indium, gallium, or their alloys) between the metal component and the polymer substrate. This interlayer acts as a mediator that bonds to both materials at a temperature below the polymer's degradation point, enabling strong bonding without thermal damage to the polymer substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the bonding temperature parameter from conventional welding/brazing temperatures (typically above 400°C) to a lower temperature range (200-400°C) suitable for polymer substrates. This is achieved by selecting interlayer materials with melting points in this lower temperature range, allowing the bonding process to occur at temperatures that preserve the polymer substrate's integrity.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional coating methods are used, then coatings are applied to metallic substrates, but the bond lacks thermal stability and robustness

Engineering Contradiction:

Improvecoating application simplicityVSAvoidthermal stability of coating bond

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent utilizes phase transition (melting and solidification) of the interlayer material to create a robust bond. The interlayer is heated to melt and flow, filling gaps and creating intimate contact with both the metal substrate and coating, then cooled to solidify, forming a strong, thermally stable bond that incorporates both the substrate and coating materials.

Inventive Principle:

Principle #36Phase transitions

3Object-affected harmful factors

If conventional fastening methods like bolts and rivets are used, then components can be joined without high heat, but the method has limitations in strength and applicability

Engineering Contradiction:

Improvethermal damage avoidanceVSAvoidbond strength and joint reliability

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent replaces mechanical fastening systems (bolts, rivets) with a thermal bonding process using a low-melting-point interlayer. This substitution creates a continuous, monolithic bond between components rather than discrete mechanical connections, eliminating issues associated with holes, stress concentrations, and fastener corrosion while maintaining thermal compatibility with polymer substrates.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 the joining of metal-coated non-metallic components to metal components without deformation, providing a robust and thermally stable bond with customized properties, overcoming the limitations of conventional joining and coating methods.

Implementation Method 1

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 produced at the bond region has solidified to form a bond

Methodology Applied

Scientific EffectMelting and solidification: Melting

Data Source

PatentUS10933489B2Transient liquid phase bonding of surface coatings metal-covered materials

Publication Date: 2021.03.02 RTX CORP

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.