Abstract
Wear and corrosion of aircraft actuator parts and helicopter gearbox rotating shafts and also wear of seals working against these parts can lead to oil leaks, which require expensive maintenance and increase the risk of failure. The Hardide nanostructured Chemical Vapor Deposition (CVD) Tungsten Carbide coating can help reduce oil leakage from gearboxes and actuators and increase maintenance intervals. The coating protects metal pistons and shafts from abrasion and corrosion, keeping their surface roughness parameters within optimum ranges for longer; this reduces seal wear and makes the whole unit more durable and reliable. The 50-100 microns thick CVD Hardide coating can be applied uniformly on internal and external surfaces and has enhanced fatigue and anti-galling properties. The coating has enhanced wear resistance outperforming Hard Chrome by 14 times and Thermal Spray WC-Co (12%) by 3 times. The fine-grain coating nanostructure wears uniformly so even worn Hardide coating shows no hard micro-grain asperities which are abrasive for seals. The coating is free from porosity and from Cobalt binder and is an excellent barrier against corrosion. As a result the coating keeps the optimal seal-friendly surface finish for longer even in abrasive and corrosive environments. The coating was qualified by Airbus as an environmentally-friendly replacement for Hard Chrome plating.
