Could Your EMI Gasket Materials be Quietly Undermining Long-Term Performance?
Galvanic corrosion in EMI gaskets often progresses unnoticed until significant shielding deterioration has occurred. Despite meticulous initial assembly, pairing dissimilar metals in gaskets and enclosures introduces an invisible yet corrosive reaction, progressively compromising shielding efficiency. Engineers frequently select gasket materials based purely on electromagnetic properties without considering the galvanic consequences of material pairings.
Understanding how galvanic corrosion arises in mixed-metal environments and proactively selecting gasket materials that inherently resist or minimize such reactions ensures sustained EMI shielding performance. Strategic choices in gasket materials and coatings decisively halt galvanic corrosion, preserving long-term electromagnetic protection.
What Exactly Causes Galvanic Corrosion in Mixed-Metal EMI Gaskets?
Galvanic corrosion results when two different metals in electrical contact share exposure to a conductive electrolyte environment, often moisture or humidity. The less noble metal undergoes accelerated corrosion, rapidly losing material integrity. EMI gaskets, typically conductive and often dissimilar from their metal enclosures, create ideal conditions for galvanic corrosion, silently reducing gasket effectiveness over time.
Identifying and carefully pairing metals based on their galvanic potential—measured using standardized galvanic series tables—allows engineers to reduce corrosion risks significantly, ensuring gasket longevity and shielding effectiveness.
How Do Material Choices Effectively Halt Galvanic Corrosion?
Selecting gasket materials with similar galvanic potentials or incorporating compatible coatings decisively prevents corrosion reactions. Recommended strategies include:
- Selecting conductive elastomers with embedded particles (nickel-plated graphite, silver-plated aluminum) that closely match enclosure metals galvanically.
- Applying protective conductive platings (tin, nickel) on metal alloy gaskets to prevent direct galvanic interactions.
- Utilizing isolation barriers, conductive adhesives, or surface treatments to interrupt corrosive pathways.
Strategically employing these methods eliminates the conditions necessary for galvanic corrosion, preserving gasket integrity indefinitely.
Safeguard Long-Term Shielding Integrity through Intentional Material Selection
Engineers decisively preserve long-term EMI shielding effectiveness by thoughtfully selecting gasket materials and compatible platings to proactively prevent galvanic corrosion. Careful consideration of galvanic compatibility in gasket material choice ensures sustained, reliable electromagnetic interference protection within mixed-metal assemblies, eliminating silent performance degradation risks.