PVD Kaplamalar Karşılaştırması: TiN vs DLC vs CrN (2026 Seçim Kılavuzu)
PVD kaplamalar için mühendis kılavuzu: TiN vs DLC vs CrN — sertlik, sürtünme, sıcaklık limiti, renk, kalınlık ve maliyet; ayrıca dekoratif vs fonksiyonel, altlık kuralları ve karar yolu.
Bir PVD kaplama, bir parçanın yüzeyini dönüştüren birkaç mikron kalınlığında seramik veya elmas benzeri bir filmdir — daha sert, daha kaygan, daha korozyona dayanıklı ya da yalnızca dökülmeyen kalıcı bir renk. Ancak "PVD" tek bir şey değildir: gerçekte aralarında seçim yapacağınız üç kaplama — altın TiN, siyah DLC ve gümüş CrN — çok farklı davranır. Bu kılavuz bir broşür değil, seçim mantığıdır.
The three coatings at a glance
| Property | TiN (gold) | DLC (black) | CrN (silver) |
|---|---|---|---|
| Hardness (HV) | ~2000–2400 | ~1500–9000 | ~1800–2000 |
| Coefficient of friction | 0.4–0.6 | 0.05–0.2 (slickest) | 0.3–0.5 |
| Max service temp | ~600 °C | ~350 °C | ~700 °C |
| Typical thickness | 1–4 µm | 1–3 µm | 2–6 µm (thicker) |
| Corrosion resistance | Good | Good | Excellent |
| Colour | Gold | Black / anthracite | Silver / metallic |
| Signature strength | Hardness + colour | Lowest friction | Thick, tough, corrosion |
What PVD actually is
PVD (physical vapour deposition) vaporises a solid metal target in a vacuum, then condenses it onto the part — usually while a reactive gas (nitrogen, a carbon source) forms the ceramic or diamond-like compound. The result is a dense, thin, extremely well-bonded film. Because it’s so thin (1–5 µm) it barely changes the part’s dimensions — the opposite of a thick plating build-up.
It’s an add-on to the machined part, so it comes after CNC work. We machine and coat under one roof through our PVD coating service, which keeps the substrate prep and coating dialled in together.
TiN — titanium nitride (the gold standard)
TiN is the original and most widely used PVD coating — the gold film you’ve seen on drill bits and taps. It’s a genuine all-rounder: hard, biocompatible, food-safe, and its gold colour is a bonus that made it a decorative favourite too.
- Best for: cutting tools, punches and dies, wear surfaces, medical instruments, decorative gold hardware.
- Strengths: high hardness, good all-round wear, biocompatible and food-safe, attractive gold colour.
- Watch-outs: higher friction than DLC; the gold colour is fixed (that’s the compound, not a dye).
- Relatives: TiCN (harder, violet-grey), TiAlN/AlTiN (higher hot-hardness for high-speed cutting).
DLC — diamond-like carbon (the slippery one)
DLC is an amorphous carbon film with a friction coefficient so low it approaches dry PTFE — but with the hardness of a ceramic. It’s the coating you choose when friction, galling or wear on sliding parts is the problem. Its deep black finish is also premium-looking, which is why it dominates high-end watches, firearms and automotive trim.
- Best for: low-friction sliding parts, engine components, pump/valve internals, firearms, luxury consumer goods.
- Strengths: lowest friction of the three (0.05–0.2), excellent wear and anti-galling, sleek black finish.
- Watch-outs: lower temperature limit (~350 °C) — not for hot cutting tools; adhesion needs careful substrate prep and often an interlayer.
- Variants: a-C:H (hydrogenated, general purpose) vs ta-C (tetrahedral, hardest, extreme wear).
CrN — chromium nitride (the tough, corrosion-proof one)
CrN trades a little hardness for toughness, thickness and outstanding corrosion resistance. It can be applied thicker than TiN or DLC without cracking, which makes it the go-to for parts that see corrosion, heat and load together — and a common modern replacement for hard chrome plating.
- Best for: dies and moulds (especially for aluminium/copper), pump and valve parts, engine components, hard-chrome replacement.
- Strengths: excellent corrosion resistance, highest temperature limit (~700 °C), can be applied thick and tough, low tendency to stick to non-ferrous work.
- Watch-outs: slightly lower hardness than TiN; silver colour is less decorative.
- Green angle: a real environmental win over hard chrome, which uses hexavalent chromium.
Beyond the big three
The big three cover most jobs, but a few specialist coatings fill the gaps:
For hotter / faster cutting
- TiAlN / AlTiN: retains hardness at high temperature — high-speed and dry machining.
- TiCN: harder than TiN with lower friction — punching, forming.
For colour / corrosion
- ZrN: light-gold / brass tone, good corrosion and biocompatibility.
- CrC / oxide variants: tuned colours and corrosion for decorative work.
The temperature limit nobody tables
This is the spec that quietly kills the wrong coating choice. Each film has a temperature above which it oxidises or degrades — and it’s not ranked the same as hardness. DLC is the hardest option in some variants but has the lowest temperature ceiling.
Decorative vs functional PVD
PVD splits into two worlds that use the same physics. Knowing which you’re buying sets the right expectations on colour tolerance, thickness and cost.
| Aspect | Decorative PVD | Functional PVD |
|---|---|---|
| Goal | Durable colour & appearance | Wear, friction, corrosion, tool life |
| Thickness | Very thin (≤1 µm) | 1–6 µm |
| Priority | Colour consistency, finish | Mechanical performance |
| Typical parts | Watches, hardware, trim, pens | Tools, dies, engine/pump parts |
| Common coatings | TiN (gold), ZrN, DLC (black) | TiN, CrN, DLC, TiAlN |
PVD colour depends on the compound and process, not a dye — so the palette is limited to what the chemistry produces (gold, black, silver, bronze, rose). For a wider colour range or non-coatable metals, compare with anodizing in our Type II vs Type III anodizing guide and the broader surface finishing guide.
Substrate & dimensional rules
- Substrate must survive the process temperature. Standard PVD runs 150–500 °C; hardened tool steels are fine, but some tempered or age-hardened parts can lose properties — check the temper.
- Dimensional impact is tiny. At 1–5 µm, PVD rarely needs tolerance compensation — unlike anodizing or plating. Still flag press-fit and thread flanks if micron-level fit matters.
- Surface finish shows through. PVD is conformal and thin, so it reveals the underlying finish. Polish before coating for gloss; the coating won’t hide machining marks.
- Clean, prepped surfaces are everything. Adhesion depends on meticulous cleaning and sometimes an interlayer (especially DLC). Oils, oxides and fingerprints cause flaking.
- Mask what shouldn’t be coated — threads, electrical contacts, mating datums where even microns matter.
How PVD is applied
1. Machine & finish the part
PVD comes last. Achieve the final surface finish first — the coating reveals, not hides, it.
2. Clean & prep
Ultrasonic cleaning and surface activation remove all oils and oxides. This step makes or breaks adhesion.
3. Load & pump down
Parts are fixtured (rotated to expose all surfaces) and the chamber is evacuated to high vacuum.
4. Ion etch / interlayer
A plasma etch cleans at the atomic level; an adhesion interlayer is applied for demanding coatings like DLC.
5. Deposit the coating
The target is vaporised (sputtering or arc) and condenses with the reactive gas to build the film micron by micron.
6. Cool, unload, inspect
Verify colour, thickness, adhesion (e.g. Rockwell/scratch test) and coverage of critical surfaces.
Which coating should you choose?
Not sure which fits your part and duty cycle? Send the drawing and the service conditions to our engineers via the PVD coating service and we’ll recommend the coating, thickness and masking before the part is coated.
Frequently asked questions
The questions engineers ask most when speccing a PVD finish.
Sıkça Sorulan Sorular
- TiN is a hard, gold, all-round coating good for tools and biocompatible parts, stable to ~600 °C. DLC is a black, diamond-like carbon film with the lowest friction (0.05–0.2), ideal for sliding and anti-galling parts, but limited to ~350 °C. CrN is a silver, tough, thick coating with the best corrosion resistance and the highest temperature limit (~700 °C), often used to replace hard chrome. Choose by the property that matters most and by the operating temperature.
- Barely. PVD films are only 1–5 µm thick, so unlike anodizing or plating they rarely need tolerance compensation. For micron-critical press-fits or thread flanks it’s still worth flagging or masking those surfaces, but for most parts the dimensional change is negligible.
- The substrate must withstand the process temperature (typically 150–500 °C). Hardened tool steels, stainless, titanium and carbide coat well; some tempered or age-hardened parts can lose properties at PVD temperatures, so check the temper. Low-temperature PVD and DLC processes exist for heat-sensitive substrates.
- No. Some DLC variants are extremely hard, but DLC has the lowest temperature ceiling of the three (~350 °C) — above that it degrades regardless of hardness. For hot applications like high-speed dry cutting or engine hot-sections, CrN or a TiAlN-family coating is the right choice even though DLC is "harder" on paper.
- The palette is limited because the colour comes from the coating compound, not a dye. Common options are gold (TiN), black/anthracite (DLC), silver (CrN), light gold/brass (ZrN) and various bronzes. For a wide custom colour range, anodizing (on aluminium) offers far more options — see our anodizing guide.
- For many applications, yes. CrN in particular is a common hard-chrome replacement: comparable or better wear and corrosion resistance, much thinner, and without the hexavalent-chromium environmental and health issues of hard chrome plating. It also avoids the hydrogen-embrittlement risk of some plating processes.
- Always machine and finish first — PVD is the last step. The coating is thin and conformal, so it reveals the underlying surface rather than hiding it: polish before coating if you want gloss. Achieve final dimensions and surface finish in machining, then coat.
What’s the real difference between TiN, DLC and CrN?
Does PVD coating change my part’s dimensions?
Can PVD be applied to any material?
Is DLC always the best because it’s hardest?
Can I get PVD in colours other than gold, black and silver?
Is PVD better than hard chrome plating?
Do I machine the part before or after PVD?
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JLYPT Engineering Team
PVD Coating & Surface Engineering Specialists
We machine parts and PVD-coat them in-house, so we see the whole chain — substrate prep, coating selection, and how the finish performs in service. This guide is the selection logic our surface-engineering team uses to match TiN, DLC or CrN to a real application instead of defaulting to whatever looks good on a brochure.
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