Corrosion-Resistant Bushing Laminate for Delamination Control

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Solution Overview

Problem

Existing maintenance-free bushings, particularly those with iron alloy substrates, face challenges in corrosion resistance and delamination when exposed to environmental conditions, leading to a need for improved corrosion resistance and longer maintenance-free lifetimes with high load capability.

Innovation Solution

A sliding article comprising a load-bearing substrate, an aluminum-containing layer, and a sliding layer, where the aluminum-containing layer is applied directly over the substrate with a thickness of at least 10 microns, and a sliding layer is applied over the substrate or aluminum-containing layer, enhancing corrosion resistance and delamination resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an iron alloy substrate is used for maintenance-free bushings, then high load-bearing capability is achieved, but corrosion resistance deteriorates when exposed to environmental conditions

Engineering Contradiction:
Improveload-bearing capabilityVSAvoidcorrosion resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention applies a multi-layer composite structure consisting of an iron alloy substrate combined with aluminum-containing layers and sliding layers. This composite approach allows the iron substrate to provide high load-bearing capability while the aluminum layers provide corrosion resistance, and the sliding layers provide low friction and wear resistance. The layers are bonded together to form an integrated structure that delivers all required functions simultaneously.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If traditional adhesive laminating is used to connect substrate and sliding layer, then manufacturing simplicity is maintained, but delamination resistance deteriorates under environmental exposure

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddelamination resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The aluminum-containing layer serves as an intermediary between the iron alloy substrate and the sliding layer. This intermediate layer improves bonding compatibility between the dissimilar materials, enhances adhesion strength, and provides corrosion protection at the interface. The aluminum layer acts as a transition zone that facilitates reliable connection while maintaining manufacturing feasibility through established metallurgical bonding processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If minimal coating thickness is applied to maintain bushing dimensions, then dimensional precision is preserved, but corrosion protection effectiveness is reduced

Engineering Contradiction:
Improvedimensional precisionVSAvoidcorrosion protection effectiveness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The protective system is segmented into multiple functional layers: an aluminum-containing layer for corrosion protection and an aluminum-containing layer for sliding and wear resistance. This segmentation allows each layer to be optimized for its specific function with appropriate thickness, providing adequate corrosion protection while maintaining overall dimensional precision of the bushing component.

Inventive Principle:
Principle #1Segmentation

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 significantly increases the corrosion resistance and maintenance-free lifetime of bushings, achieving a corrosion resistance rating of at least 1000 hours and maintaining high load-bearing capacity, as demonstrated by neutral salt spray tests and SEM analysis.

Implementation Method 1

an aluminum-containing layer, where the aluminum-containing layer is applied directly over the substrate

Methodology Applied
Scientific EffectGalvanic protection:

Implementation Method 2

achieving a corrosion resistance rating of at least 1000 hours

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

a sliding layer is applied over the substrate or aluminum-containing layer, enhancing corrosion resistance and delamination resistance

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4043204A1Corrosion resistant bushing
Publication Date: 2022.08.17 SAINT GOBAIN PERFORMANCE PLASTICS PAMPUS GMBH
  • EP4043204A1 patent drawingFigure 1A~1D
  • EP4043204A1 patent drawingFigure 2A~2B
  • EP4043204A1 patent drawingFigure 3A~3B

AI summary

A method of forming a corrosion resistant bushing includes bonding a sliding layer to a first surface of a load bearing substrate to form a laminate sheet and cutting a blank from the laminate sheet. The laminate sheet includes an exposed surface corresponding to a second surface of the load bearing substrate. The blank includes cut edges having a load bearing substrate portion. The method further includes forming a semi-finished bushing from the blank.