New coatings for composite aircraft wings
Aircraft designers are increasingly turning to composite materials to make their vehicles lighter and therefore more fuel efficient. Although composites offer the advantages of high strength-to-weight ratios, low density and low thermal expansion coefficients, they are susceptible to damage just like any other material. Typical cases include rain erosion or thermomechanical fatigue due to sustained exposure to high temperatures at high altitudes. Within the EU-funded project COMPOCOAT (Coatings for composite aero-engine structures), researchers developed new coatings based on aluminium to protect metallic leading edges against erosion and the composite wing from thermal fatigue. The new surface protection technology is based on TWI's CompoSurf family of coatings deposited by a thermal spraying process. The team conducted a number of tests demonstrating the ability of the high-quality coating to create a rough surface and resist wear, erosion and corrosion. In addition to surface protection technology, researchers utilised a joining process to achieve high-strength bonding between the composite structure and the metallic leading edge. Laser welding was tested as a potential method for joining the leading edge without causing any negative thermal impact on the composite. Advanced coatings can decrease aerodynamic drag on the wing surface and thus reduce fuel consumption.
Keywords
Coatings, composite aircraft wings, COMPOCOAT, leading edges, surface protection
