Design for Corrosion and Galvanic Compatibility Best Practices

Corrosion and Galvanic Compatibility Knowledge

The corrosion design techniques discussed in this section are a summary of recommended Dos based on features that have displayed significant impact on the durability and reliability of your product and equipment in service.

Dos

  • Design on the assumption that moisture and other corrosive mechanism will be present.
  • Seal all dissimilar metal (galvanic) couples.
  • Use conformal coating on printed wiring boards.
  • Use as easily replaceable anodic (consumable) part in assembling grounding or bonding connections.
  • Use only electrical connector boots that can be sealed with adhesives.
  • Carefully select a protective system for use on magnesium.
  • Complete the working of aluminum, steel, etc (drilling, cutting, grinding) prior to surface treatment.
  • Use surface treatments (anodize and conversion coatings) on aluminum.
  • Carefully select the metal plating use to provide sacrificial protection, barrier protection, as a third metal between two otherwise incompatible metals, or as a substitute surface.
  • Use a nickel strike under gold plating.
  • Use solder flux with lowest possible acid content.
  • Use metallic materials with the most corrosion resistant configuration (passivated) with minimum possible residual stressing.
  • Use fluorocarbon or fluorosilicone type materials for gaskets, O rings an seals.
  • Use low point drains.
  • Mount equipment an components at least 1/2 inch above potential standing water level.
  • Use hermetic sealing where possible.
  • Design for maintainability.
  • Use shoe box lids on enclosures.
  • Mount PWBs vertically with the edge connectors on vertical edge or back of board.
  • Mount electrical connectors horizontally.
  • Use drip loops on electrical cables and piping.
  • Use desiccant systems with visual indicators.
  • Use cooling systems that remove moisture and particulate matter.
  • Use O rings to seal around control shafts that must penetrate into an corrosive environment.
  • Be aware of various interior and exterior fluids which your product will be exposed to.
  • Recognize the operational environment.
  • Recognize the maintenance environment.
  • Be aware of  maintenance procedures and materials.
  • Listen to feedback!