Anti-corrosion Thread Compound for Seawater Galvanic Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional thread compounds fail to effectively prevent corrosion between galvanically disparate metals in seawater environments, such as stainless steel and aluminum, as they are often incompatible and have limited efficiency.

Innovation Solution

An anti-corrosion compound comprising a hydrocarbon grease blended with aluminum/indium/zinc powder, where the hydrocarbon grease constitutes 55-80% by volume and the aluminum/indium/zinc powder constitutes 20-45% by volume, is used to protect threads of bolts and hardware from corrosion in seawater environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional thread compounds with nickel, zinc, molybdenum, graphite, copper, or silver powder additives are used, then some corrosion protection is provided, but the compounds are galvanically incompatible with the components and have limited efficiency

Engineering Contradiction:

Improvecorrosion protection effectivenessVSAvoidgalvanic compatibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent uses an aluminum/indium/zinc powder blend as an intermediary substance applied to the stainless steel bolt threads. This compound acts as a mediator between the noble metal (stainless steel) and base metal (aluminum) components, preventing direct galvanic contact while providing corrosion protection. The aluminum-based powder creates a compatible interface that eliminates the harmful galvanic effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical composition parameters of the thread compound from conventional metals (nickel, zinc, copper) to an aluminum-based alloy powder containing indium and zinc. This parameter change in the compound's composition makes it galvanically compatible with both stainless steel and aluminum components, resolving the incompatibility issue while maintaining protective functionality.

Inventive Principle:

Principle #35Parameter changes

2Strength

If stainless steel bolts are attached to aluminum structures in seawater environment, then strong fastening is achieved, but the aluminum structure quickly corrodes due to galvanic action

Engineering Contradiction:

Improvefastening strengthVSAvoidcorrosion of aluminum structure

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The aluminum/indium/zinc powder compound is applied to the bolt threads before assembly, creating a pre-protective layer that prevents galvanic corrosion before it can occur. This preliminary application of the protective compound counteracts the harmful galvanic effect that would otherwise quickly corrode the aluminum structure in seawater environments.

Inventive Principle:

Principle #9Preliminary anti-action

3Ease of manufacture

If aluminum structures are placed in contact with stainless steel bolts, then assembly is achieved, but the aluminum quickly corrodes in seawater environment

Engineering Contradiction:

Improveassembly capabilityVSAvoidcorrosion resistance of aluminum

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The thread compound serves as an intermediary layer between the stainless steel bolt and aluminum structure, enabling assembly while preventing the harmful interaction. The aluminum-based powder in the compound is galvanically compatible with the aluminum structure, eliminating the corrosion problem while maintaining assembly functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 compound significantly reduces or eliminates corrosion between galvanically disparate metals, providing a minimum of two years of protection in seawater exposure, as demonstrated by Marine Accelerated Life Tests, outperforming conventional methods by increasing corrosion resistance by at least a factor of two.

Implementation Method 1

When exposed to seawater environments, parts made of galvanically disparate metals will quickly corrode. For example, stainless steel bolts (noble metal) attached to aluminum structures (base metal) in a seawater environment will cause the aluminum to quickly corrode.

Methodology Applied

Scientific EffectGalvanic protection: