June 17th, 2021
Carbon composites are a broad class of materials in which carbon structures (typically fibers) are dispersed throughout a bulk material. As with other composite materials, carbon composites are “more than the sum of their parts”, offering superlative strength and stiffness while remaining relatively lightweight. The properties of carbon composites lend themselves to widespread use as engineering materials, in particular in the aerospace and aviation industries.
Development of Carbon Composites for Aerospace Applications
The aerospace industry places extraordinarily high demands on its materials and components – to the point where the term “aerospace grade” has become practically synonymous with “high tech”. If a material is defined as strong, stiff and lightweight, there is a great likelihood that it has been investigated for use in aircraft and aviation applications.
Carbon composites are, in many ways, an excellent aerospace material. Consisting of a carbon ‘filler’ dispersed throughout a bulk ‘matrix’ (typically a polymer such as PTFE), carbon composite components boast incredible stiffness while also exhibiting much lower density than materials with comparable mechanical properties.
Carbon composites were first used in aircraft structures following the discovery of carbon fiber at the Royal Aircraft Establishment in Farnborough, UK, in 1964. The newly-developed carbon fibers were dispersed in polymers to reinforce them, resulting in a class of composite materials known as Carbon Fiber Reinforced Plastics (CFRPs). As these materials evolved – with the use of improved fibers and matrix materials – their high stiffness and strength-to-weight ratios enabled them to displace more conventional materials like aluminum and titanium alloys for primary structures.
Today, carbon composites make up a significant portion of virtually any aircraft’s weight. For example, the vertical stabilizer of an Airbus A310 – a primary aerodynamic and structural component – is fabricated in its entirety from carbon composite. This component offers a huge weight saving of almost 400 kg when compared with the previously-used unit which was made from an aluminum alloy.
Advantages of Carbon Composites for Aircraft Bodies
The primary motivation for incorporating carbon composites into aircraft bodies was that it provided comparable stiffness and strength to conventional aluminum and titanium alloys while offering a significantly decreased mass. Despite the increased cost of producing composites, the reduction in mass is often worth it. Even modest weight reductions can save thousands of dollars of fuel over the course of a year; therefore, making aircraft bodies from carbon composites often results in much lower lifetime costs.
Carbon composites can offer increased fabricability compared to metals. As well as enabling more aerodynamic (and thus more fuel-efficient) aircraft bodies, the use of composites can enable a reduction in radar-cross section and incorporation of radar absorbent materials for military aircraft.
Reduced Number of Parts
Unlike metals, carbon composites can be molded. This means that multiple simple metal parts can be replaced with a single complex carbon composite piece, thereby significantly reducing the number of parts needed to build the airplane.
Carbon Composites from Saint-Gobain Seals
Saint-Gobain Seals leverages a wealth of experience in materials research to provide a comprehensive array of carbon composite components to the aviation industry.
Along with composite solutions, their OmniSeal®, Meldin® and Rulon® sealing and material solutions are available in custom designs and a variety of formulations to precisely fit any aviation or space application. Common applications of carbon composites in aerospace systems include actuators, landing gear, and bleed air systems.
To learn more about Saint-Gobain Seals and how carbon composite materials can support your aviation or space application, reach out to an expert today.