Aerospace components do not fail in the same way as industrial parts. They fail under sustained thermal cycling between extremes, under constant vibration that drives fretting at mating surfaces, and under mechanical loads that persist for thousands of flight hours without maintenance access. The consequences of surface failure in aerospace are measured in grounded aircraft, failed inspections, and safety margins that cannot be compromised.
This is why aerospace parts cannot rely on general-purpose surface coating specifications. They require coatings selected, applied, and documented specifically for the operating conditions that define aerospace service.
Advanced Coating Technologies (ACT) applies PVD and DLC coatings to aerospace components under AS9100D and ISO 9001:2015 quality controls. Here is what makes aerospace surface treatment requirements different from every other industry.
Aerospace components, including bearings, gears, valves, molds, and precision mechanisms, operate in environments that push standard coatings past their limits.
Sustained high temperatures are common in components located near propulsion systems, bleed air ducts, and hydraulic systems that generate heat during operation. A coating rated to 600°C (like TiN) may be adequate for a machine shop cutting tool but inadequate for an aerospace bearing cycling between ambient and 650°C+ repeatedly over its service life.
Thermal cycling, the repeated expansion and contraction as temperatures rise and fall, stresses the bond between coating and substrate. A coating with marginal adhesion may survive a static high-temperature test but delaminate after hundreds of thermal cycles. Aerospace coatings must maintain adhesion through this cycling without degradation.
Fretting, the adhesive transfer of material between contacting surfaces under vibration, is a failure mode almost unique to aerospace in its severity. Fretting initiates micro-cracks that propagate under fatigue loading, eventually leading to component failure. Coatings that reduce friction and resist material transfer at the contact interface directly address this mechanism.
Ultrathin PVD coatings for aerospace parts are applied at 1 to 4 µm precisely because aerospace tolerances cannot absorb the dimensional buildup of thicker surface treatments. A bearing raceway ground to single-digit micrometer tolerances cannot accept a 50 µm chrome plate without post-coating grinding, which adds cost, lead time, and the risk of introducing new surface defects. Electroplated finishes also carry the risk of hydrogen embrittlement on high-strength steels and superalloys, a concern that PVD's dry vacuum process eliminates.
PVD coatings at 1 to 4 µm preserve the finished geometry of precision-ground, honed, or lapped surfaces. The coating adds hardness, friction reduction, and oxidation resistance without changing the dimensions that were specified and verified before coating. A 3 µm coating on a cylindrical component adds just 6 µm to the total diameter, a dimensional change that falls within the tolerance bands of virtually all qualified aerospace parts.
For aerospace components where form, fit, and function are qualified to tight tolerance bands, this dimensional neutrality is a requirement, not a convenience. Requalifying a part because the surface treatment pushed it out of specification creates delays, additional inspection costs, and potential disruption to the production schedule. PVD avoids that risk by design.
Aerospace coating selection follows the same data-driven framework used in any application, but the stakes narrow the acceptable options.
For components exposed to sustained temperatures above 600°C, AlTiN (HV 3,400 to 3,600, max 700°C) provides oxidation resistance with its self-forming aluminum oxide layer. For the most demanding thermal conditions, AlTiSiN and nACO (HV 4,500, max 1,200°C) maintain hardness and adhesion at temperatures that would destroy standard coatings.
For precision mechanisms with sliding contact, DLC (COF 0.05 to 0.1) reduces friction without lubricants. In vacuum and space applications where liquid lubricants evaporate or outgas, X-LC (COF 0.02 in nitrogen) and X-LC Shadow (HV 3,500, COF 0.10) provide dry lubrication that functions where nothing else can.
CrN (HV 1,800, COF 0.30, max 700°C) provides corrosion resistance for components exposed to hydraulic fluids, cleaning solvents, and environmental moisture.
In aerospace, a coating without documentation is a coating that does not exist. AS9100D requires full lot traceability linking every coated part to its specific coating run, process parameters, inspection results, and raw material batch. This documentation supports first-article inspections, periodic audits, and root-cause investigations if a coated part fails in service.
At ACT, aerospace parts receive the same documented process that governs every job through our AS9100D and ISO 9001:2015 certified facility. In-house testing with Calo Testers, Fisherscope X-ray systems, Tribo Meters, and optical microscopes verifies thickness, adhesion, friction, and surface quality before parts ship. The coating protects the component. The documentation protects the program. Aerospace surface coating work requires that both perform without exception.
Copyright © 2012 - 2026 | Advanced Coating Technologies, Inc.
