Requirements in aerospace

In aerospace, demanding materials and complete traceability characterise the cleaning processes. Processes have to be gentle, controlled and traceable — at consistent, documentable quality.

A large part of this work involves the reconditioning of components from flight operations: operational contamination on engine and landing-gear components is removed for further use.

Typical components and materials

From this industry, we mainly clean:

Components: the typical aerospace components, above all engine and landing-gear parts
Materials: titanium, aluminium alloys, CFRP/composites, nickel-based alloys as well as high-strength steels
Contamination: operational contamination from flight operations

Reconditioning and overhaul

A focus of TeSe’s aerospace work is the reconditioning of components from overhauls. For cleaning and degreasing, systems from Karl Roll GmbH are used; the media are solvents and aqueous cleaners from ZET-Chemie. The parts processed are above all engine and landing-gear components. The same revision/overhaul principle applies to the related field of rail vehicle technology.

Suitable processes

For cleaning and degreasing during overhaul, wet-chemical processes take priority. Depending on the part, the contamination and the approval, further processes are added — we advise on a technology-neutral basis. For this industry, the following are particularly relevant:

Wet-chemical cleaning — aqueous or solvent-based cleaning, also for oils and greases
Laser cleaning — selective, contactless removal of defined contamination
Plasma & corona pre-treatment — fine cleaning and surface activation without chemicals
CO₂ snow blasting — dry, residue-free cleaning of sensitive materials

Avoiding hexavalent chromium (Cr(VI)): laser and plasma pre-treatment

One concrete case involved aluminium housing parts in rocket construction that are bonded in the aerospace sector: to avoid the chromate conversion coating with hexavalent chromium (Cr(VI)) there, the combination of laser and plasma pre-treatment prepares the surface so that these housing parts can be bonded without primer or a chromium-based conversion coating — laser cleaning removes defined layers, plasma treatment activates the surface for a durable adhesive bond.

The approach has demonstrably worked. Whether it is used depends on the approval and the cost-effectiveness of the respective project — both are decisive in the aerospace sector.

Testing and traceability

Traceability is central in the aerospace sector. Alongside the usual testing methods — in-house, for instance, contact angle measurement and microscopy — it is above all the NDT processes prescribed by the aircraft manufacturers (OEMs) that are relevant. Which tests and standards specifically apply is customer- and manufacturer-specific; TeSe aligns its processes accordingly.

Practical example

At a large maintenance provider (MRO), several cleaning and degreasing systems from Karl Roll GmbH are in operation — for reconditioning the components arising from overhauls, above all engine and landing-gear components.

Frequently asked questions

What does TeSe clean in the aerospace sector? Above all engine and landing-gear components — predominantly as part of reconditioning (overhaul).

Which systems and media are used? Cleaning and degreasing systems from Karl Roll GmbH with solvents and aqueous cleaners from ZET-Chemie.

Can chromate conversion coating (hexavalent chromium/Cr(VI)) be avoided on aluminium? With a combination of laser and plasma pre-treatment for primer-free bonding, this has been demonstrably proven. Its use depends on the approval and cost-effectiveness of the project.

What about traceability and standards? Traceability is central. The specific tests (including NDT) and standards are customer- and manufacturer-specific.

Test the process at TeSe

Whether a process meets your industry’s requirements on your actual part is shown by a trial: 1–2 hours of testing free of charge. In-depth feasibility studies: CHF 1’200 per day, 50% creditable against a machine purchase.