Coating & Surface Treatment
Also known as: PVD, CVD, Thermal Spray, Electroless Nickel, Anodising, DLC, Plating, Passivation
Coating and surface-treatment processes deposit or convert a surface layer on AM parts to add wear resistance, corrosion resistance, thermal protection, electrical properties, or dimensional build-up. Key families: PVD/CVD hard coatings (TiN, TiAlN, CrN, DLC) for tooling and wear surfaces; thermal spray (HVOF, plasma) for thick functional layers and dimensional reclamation; electroless nickel for uniform corrosion/wear layers on complex geometry; anodising for aluminium; and chemical passivation for stainless corrosion resistance.
Why AM parts need this
AM parts often need surface properties the bulk material cannot provide. AM tool-steel inserts gain wear life from PVD TiAlN; AM aluminium gains corrosion and wear resistance from hard anodising; AM stainless implants and food-contact parts are passivated per ASTM A967. Electroless nickel is especially valuable for AM because it deposits a uniform layer over complex geometry, internal features, and lattices that line-of-sight PVD cannot coat evenly. Thermal spray reclaims worn or under-tolerance AM surfaces and applies thermal-barrier coatings to AM turbine components. Most coatings require a controlled input surface — as-built AM roughness usually needs reduction (blasting, machining, or EP) before coating for adhesion and uniformity.
Key parameters
TiN/TiAlN/CrN/DLC. Thin, conformal, line-of-sight. Hardness 2000–3500 HV. Deposited at 200–500 °C — check substrate tempering temperature.
Uniform over complex geometry and internal features (autocatalytic, not line-of-sight). EN-PTFE and EN-SiC composites available.
HVOF WC-Co, plasma ceramics. Thick functional layers and dimensional reclamation. Line-of-sight; rougher than PVD.
For AM aluminium (AlSi10Mg). Note: high-Si AM aluminium anodises to a darker, less uniform finish than wrought — validate cosmetics.
Most coatings need a prepared surface for adhesion/uniformity. As-built AM Ra (8–25 µm) usually needs blasting, machining, or EP first.
Compatible AM processes
Compatible materials
Limitations
- PVD/CVD and thermal spray are line-of-sight — they cannot coat internal channels or deep recesses uniformly (use electroless nickel for those)
- Coating adhesion depends on surface preparation — as-built AM roughness usually must be reduced first
- PVD/CVD deposition temperatures (200–900 °C) can over-temper hardened AM substrates — confirm thermal compatibility
- High-silicon AM aluminium (AlSi10Mg) anodises non-uniformly versus wrought — cosmetic results differ
- Thermal-spray and thick coatings change dimensions — account for build-up in tolerancing
Related tools
Providers
Oerlikon Surface Solutions (BALZERS / Metco)
Oerlikon's coatings and thermal spray division — PVD/CVD hard coatings (BALZERS brand) and thermal spray (Metco brand) applied to AM tooling and structural parts for enhanced wear, corrosion, and thermal performance.
Pfäffikon, CH
Kennametal Surface Solutions
Global provider of hard-facing, PVD/CVD coating, and thermal spray services that extend the service life of AM tooling and wear-resistant components.
Pittsburgh, PA, US
Surface Technology
UK metal finishing specialist applying electroless nickel, PTFE composite, and specialist coatings to AM metal parts for corrosion resistance, wear resistance, and dimensional build-up.
Nottingham, GB
Aalberts Surface Technologies
Dutch industrial group offering a broad portfolio of thermal, chemical, and physical surface treatments engineered for AM aerospace and automotive parts.
Utrecht, NL
Plasmatreat — Openair-Plasma for AM
Steinhagen Germany atmospheric plasma specialist — Openair-Plasma jet systems used to activate AM polymer and metal surfaces before bonding, painting, or overmoulding, replacing chemical surface pretreatments.
Steinhagen, DE
Relevant standards
Coating thickness and hardness ranges from Oerlikon Balzers, Kennametal, and Surface Technology published data (manufacturer tier). Standards per ASTM B733 (electroless nickel), ASTM A967 (passivation), ISO 4527.
All post-processing