Electroplated Conductor Rod Coatings for Liquid-Metal Corrosion Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing systems for providing electrical power to heavy work machines using conductive liquids face challenges due to corrosion issues with typical electrical conductors, and existing barrier deposition methods are complex and limited in application.

Innovation Solution

A conductor rod system with a barrel conductor and a cylinder conductor, where a conductive liquid is contained within a liquid space defined by the interior surface of the cylinder conductor and the outer surface of the barrel conductor, and electroplated corrosion barriers are used on both surfaces to prevent corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If liquid metal media is used as conductive media to maintain electrical contact, then electrical conductivity and adaptability are improved, but corrosion resistance deteriorates

Engineering Contradiction:

Improveelectrical conductivityVSAvoidcorrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A corrosion barrier layer is introduced as an intermediary between the liquid metal media and the electrical conductor. This barrier layer is electrically conductive while protecting the underlying conductor from corrosion by the liquid metal, thus maintaining electrical conductivity while eliminating the harmful corrosive effect

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical contact system uses a composite structure consisting of multiple layers: the base electrical conductor (copper, aluminum, or alloy), an intermediate corrosion barrier layer (such as nickel, cobalt, or their phosphides), and the liquid metal media. This composite structure combines the electrical conductivity of the base metal with the corrosion resistance of the barrier layer

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If sandblasting and painting processes are used to deposit corrosion barrier, then corrosion resistance is improved, but manufacturing complexity and time increase

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The mechanical sandblasting and painting process is replaced with an electrochemical deposition process (electroplating or electroless plating). This substitution eliminates the need for complex surface preparation steps like sandblasting and curing, while providing a more controlled and uniform corrosion barrier layer deposition

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The manufacturing process transitions from mechanical/thermal parameters (sandblasting intensity, paint curing temperature) to electrochemical parameters (plating current density, electrolyte composition, deposition time). This parameter change enables more precise control over barrier layer thickness and properties, reducing manufacturing complexity

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If sandblasting chamber is used for surface treatment, then corrosion barrier deposition is improved, but adaptability to different component sizes is limited

Engineering Contradiction:

Improvecorrosion barrier qualityVSAvoidcomponent size adaptability

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The sandblasting chamber mechanical system is replaced with an electrochemical deposition system that can accommodate components of various sizes. The electroplating or electroless plating process allows the component to be immersed in the electrolyte solution, enabling uniform barrier layer deposition on complex geometries without size restrictions imposed by chamber volume

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

The electroplated corrosion barriers effectively protect the conductor surfaces from corrosion, allowing the use of conductive liquids while maintaining reliable electrical connections, thus improving the operational lifespan and efficiency of the conductor rod system.

Implementation Method 1

electroplated corrosion barriers are used on both surfaces to prevent corrosion

Methodology Applied

Scientific EffectElectroplating: Electroplating

Implementation Method 2

a liquid junction formed from the liquid space, the first corrosion barrier, the second corrosion barrier, and the conductive liquid, the liquid junction configured to electrically connect the barrel conductor to the cylinder conductor

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS20250033484A1Electroplated coatings for conductor corrosion resistance

Publication Date: 2025.01.30 CATERPILLAR INC

AI summary

A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. Electrical connectivity between conductors within the conductor rod, between the concentric metal tubes, are provided using a conductive liquid. Corrosion barriers are used to protect the concentric metal tubes from corrosion resulting from contact with the conductive liquid. The corrosion barriers are electroplated and include nickel phosphide and/or cobalt phosphide to maintain the electrical connectivity between the conductors, while protecting the conductors from corrosion.