Technical Fibre Products (TFP), a leading nonwoven manufacturer, presents dielectric nonwovens that can be used to help prevent galvanic corrosion, a common and destructive problem when aluminium or other metals come into contact with carbon fibre 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, the manufacturer reprots.

The company will exhibit its latest developments and products at the upcoming SAMPE exhibition, which takes place in Baltimore from 19-20 May.

Galvanic corrosion

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 aluminium components or between a carbon reinforcement and aluminium honeycomb. Carbon fibre is a good electrical conductor and can produce a large galvanic potential with aluminium.

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, the company reports.

Prevention of galvanic corrosion

The issue of galvanic corrosion is not limited to aluminium 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 aluminium simultaneously. To achieve this, the materials must be separated, for example, by using one of TFP’s dielectric nonwovens, which acts as an electrically isolating layer, providing a barrier to galvanic corrosion by preventing the electrochemical reaction.

Prevention of galvanic corrosion is just one application for TFP’s nonwovens, which fulfil a number of purposes, according to the manufacturer. These include improved surface finish for composites, resin flow media, improving interlaminar fracture toughness of a composite structure, and imparting functionality, such as abrasion resistance.

www.tfpglobal.com