Technical Fiber Products (TFP) says that its dielectric nonwovens can be used to prevent galvanic corrosion, a common and destructive problem when aluminum or other metals come into contact with carbon fiber in a composite structure.
The nonwoven can prevent this by providing an extremely uniform, lightweight barrier between the two materials to isolate them, stopping an electrochemical reaction occurring.
Galvanic corrosion, also known as dissimilar metal corrosion, can occur when two dissimilar conductive materials can come into contact in the presence of an electrolyte (such as water) and a pathway for electron transfer is created. In a composite context, this could mean contact between carbon composite and aluminum components or between a carbon reinforcement and aluminum honeycomb. Carbon fiber is a good electrical conductor and can produce a large galvanic potential with aluminum. The result of this is surface corrosion and extensive pitting; this can be very serious, particularly in instances where it occurs out of sight, as undetected, it may cause structural failure.
Separating materials
The issue of galvanic corrosion is not limited to aluminum and can occur with other metals and alloys, such as steel or stainless steel, in certain environmental conditions.
The solution to stop galvanic corrosion occurring is to prevent moisture coming into contact with the carbon and the aluminum simultaneously. To achieve this, the materials must be separated. This can be achieved using a dielectric nonwovens which acts as an electrically isolating layer, providing a barrier to galvanic corrosion by preventing the electrochemical reaction.
TFP’s nonwovens also offer improved surface finish for composites, resin flow media, improved interlaminar fracture toughness of a composite structure or functionality such as abrasion resistance, the company says.
This story is reprinted from material from TFP, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
