Diamond-like carbon DLC

spore: profile
id: diamond-like-carbon
spore_version: 0.2
family: diamond-like-carbon
name: Diamond-like carbon
abbreviation: DLC
role: hard low-friction coating
category: carbon
type: diamond
summary: |
  Diamond-like carbon (DLC) is an amorphous carbon coating with a mix of sp3 (diamond-type) and sp2 (graphite-type) bonds. A PECVD DLC film made from hexane measured 9.1 GPa nanoindentation hardness and 79.0 GPa modulus in one laboratory study. The NACL DLC data sheet gives a Vickers hardness of 1000 to 3000 HV and a maximum working temperature of 500 °C, with no test or formulation stated.
best_for: Hard wear surfaces on sliding parts and optics. NACL lists a Vickers hardness of 1000 to 3000 HV, depending on formulation
weakest_at: 'Erosion in oxygen plasma: 434 Å/min in a laboratory test, with hardness falling from 9.1 GPa to 6.3 GPa after the test; no orbital erosion data were found'
identity:
  formula: C (amorphous carbon with sp3 and sp2 bonding; some grades contain hydrogen, written a-C:H)
  source: wikipedia-dlc
  where: 'Definition paragraph: DLC is a class of amorphous carbon materials that display some of the typical properties of diamond'
tags:
  environments:
    - low-earth-orbit
  stresses:
    - atomic-oxygen
  applications:
    - mechanisms
    - optics-and-cameras
properties:
  - benchmark: hardness_vickers
    label: Hardness (Vickers), NACL DLC coating
    value: 1000
    value_high: 3000
    bound: range
    unit: HV
    scope: material
    conditions:
      basis: formulation dependent, as printed by the manufacturer
    method: Manufacturer material properties table; no test load is printed
    status: ground
    source: nacl-dlc-tds
    where: Page 2, Diamond Like Carbon Material Properties table, row 'Hardness (Vickers)'
  - benchmark: friction_coefficient
    label: Friction, NACL DLC coating (as-deposited)
    value: 0.1
    bound: upper
    unit: '-'
    scope: material
    conditions:
      state: as-deposited
      printed: <0.1
    method: Manufacturer material properties table; no test method is printed
    status: ground
    source: nacl-dlc-tds
    where: Page 2, Diamond Like Carbon Material Properties table, row 'Friction'
  - benchmark: max_service_temp
    label: Maximum working temperature, NACL DLC coating
    value: 500
    unit: °C
    scope: material
    conditions:
      basis: printed as Max. Working Temp.; no coating formulation or test is stated
    method: Manufacturer material properties table
    status: ground
    note: No test or formulation is printed for this rating.
    source: nacl-dlc-tds
    where: Page 2, Diamond Like Carbon Material Properties table, row 'Max. Working Temp.'
  - benchmark: deposition_temperature
    label: Deposition temperature, NACL DLC coating
    value: 50
    bound: upper
    unit: °C
    scope: material
    conditions:
      printed: <50 °C
    method: Manufacturer material properties table
    status: ground
    source: nacl-dlc-tds
    where: Page 2, Diamond Like Carbon Material Properties table, row 'Deposition Temp.'
  - benchmark: refractive_index
    label: Refractive index, NACL DLC coating
    value: 1.5
    value_high: 2.1
    bound: range
    unit: '-'
    scope: material
    conditions:
      basis: depends on formulation and substrate, as printed
    method: Manufacturer material properties table
    status: ground
    source: nacl-dlc-tds
    where: Page 2, Diamond Like Carbon Material Properties table, row 'Refractive Index'
  - benchmark: coating_thickness
    label: Coating thickness, hydrogen-free Ta-C coating (Misumi)
    value: 0.2
    value_high: 1
    bound: range
    unit: µm
    scope: material
    conditions:
      coating: Ta-C, PVD, hydrogen-free
    method: Manufacturer datasheet
    status: ground
    source: misumi-dlc
    where: Properties table, row 'Thickness [µm]'
  - benchmark: surface_roughness_rz
    label: Surface roughness Rz, Ta-C coating (Misumi)
    value: 1
    bound: upper
    unit: µm
    scope: material
    conditions:
      coating: Ta-C, PVD
      printed: <1
    method: Manufacturer datasheet
    status: ground
    source: misumi-dlc
    where: Properties table, row 'Surface roughness Rz [µm]'
  - benchmark: hardness_nanoindentation
    label: Hardness (H), DLC from hexane by PECVD, as deposited
    value: 9.1
    unit: GPa
    scope: material
    conditions:
      film: DLC from hexane by pulsed DC PECVD, not corroded
      load: 10 mN, 12 indentations per sample
      uncertainty: plus or minus 2.8 as printed
    method: Nanoindentation as described in Section 2 of the paper
    status: ground
    source: ferreira2021
    where: Table 4, row 'DLC non-corroded'
  - benchmark: hardness_nanoindentation
    label: Hardness (H), DLC from hexane by PECVD, after oxygen-plasma corrosion
    value: 6.3
    unit: GPa
    scope: material
    conditions:
      film: DLC from hexane by pulsed DC PECVD, corroded in oxygen plasma
      load: 10 mN, 12 indentations per sample
      uncertainty: plus or minus 1.8 as printed
    method: Nanoindentation as described in Section 2 of the paper
    status: ground
    source: ferreira2021
    where: Table 4, row 'DLC corroded'
  - benchmark: elastic_modulus
    label: Modulus E, DLC from hexane by PECVD, as deposited
    value: 79
    unit: GPa
    scope: material
    conditions:
      film: DLC from hexane by pulsed DC PECVD, not corroded
      uncertainty: plus or minus 13.0 as printed
      labelled_as: E (GPa) in Table 4; the extract does not define E
    method: Reported beside the hardness values in Table 4
    status: ground
    source: ferreira2021
    where: Table 4, column E (GPa), row 'DLC non-corroded'
  - benchmark: plasma_etch_rate
    label: Corrosion (etch) rate of DLC in oxygen plasma
    value: 434
    unit: Å/min
    scope: material
    conditions:
      plasma: oxygen, 12 sccm, RF 13.5 MHz, 10 W, bias -179 V, lower electrode 23 °C
      film: DLC from hexane by PECVD
    method: Laboratory oxygen-plasma exposure reported in Table 2; not a flight test and not an erosion yield
    status: ground
    note: Printed as 434 ± 26 Å/min.
    source: ferreira2021
    where: Section 2 (corrosion conditions) and Table 2, row 'DLC'
  - benchmark: raman_id_ig_ratio
    label: Raman intensity ratio ID/IG, DLC as deposited
    value: 0.4
    unit: '-'
    scope: material
    conditions:
      film: DLC from hexane by PECVD, not corroded
      uncertainty: plus or minus 0.05 as printed
    method: Raman spectroscopy as reported in Table 4
    status: ground
    source: ferreira2021
    where: Table 4, column ID/IG, row 'DLC non-corroded'
  - benchmark: critical_load_lc1
    label: First critical load LC1, DLC scratch test
    value: 11.2
    unit: 'N'
    scope: material
    conditions:
      film: DLC from hexane by PECVD
      test: scratch test with normal load from 0.2 N to 30 N over 10 mm, sliding speed 0.1 mm/s
      uncertainty: plus or minus 1.8 as printed
    method: Scratch test as described in Section 3
    status: ground
    note: The paper gives a different mean critical load for the same DLC film in Section 3 and a different range in the abstract. The sources disagree, so the value here is the LC1 figure only.
    source: ferreira2021
    where: Section 3 (Adhesion), LC1 value printed for DLC
  - benchmark: density
    label: Density of a simulated dense ta-C network
    value: 2.99
    unit: g/cm3
    scope: material
    conditions:
      network: simulated dense tetrahedral amorphous carbon, sp3 bonding fraction 79%
      basis: simulation, not a measured film
    method: Tight-binding molecular dynamics and Monte Carlo simulation, per the abstract
    status: calculated
    note: Printed as 2.99 gcm−3 in the paper. No measured bulk density for a DLC film was recorded in this run.
    source: fyta2006
    where: Results, description of Fig. 1(a)
  - benchmark: sp3_fraction
    label: sp3 bonding fraction of the same simulated network
    value: 79
    unit: '%'
    scope: material
    conditions:
      network: simulated dense ta-C, density 2.99 g/cm3
    method: Tight-binding molecular dynamics and Monte Carlo simulation, per the abstract
    status: calculated
    source: fyta2006
    where: Results, description of Fig. 1(a)
  - benchmark: friction_coefficient
    label: Steady-state friction coefficient, ion-beam DLC on silicon, ultrahigh vacuum
    value: 0.1
    bound: upper
    unit: '-'
    scope: material
    conditions:
      film: ion-beam-deposited DLC from an argon and CH4 mixture at 1500 or 700 eV ion energy
      environment: ultrahigh vacuum; the report also tests humid air, dry nitrogen and water
      test: unidirectional rotating sliding at room temperature
    method: Sliding friction test; the report prints the value as a bound
    status: ground
    note: The abstract prints low steady-state coefficients of friction (<0.1) for DLC in every environment tested.
    source: miyoshi1997
    where: Abstract; Coefficients of Friction and Wear Rates section
  - benchmark: coating_thickness
    label: Thickness, ion-beam DLC films on silicon
    value: 520
    value_high: 660
    bound: range
    unit: nm
    scope: material
    conditions:
      film: ion-beam-deposited DLC, argon and CH4 in a 3:17 mixture
      note_source: the report cites Wu et al. (1995) for this range
    method: Stated in the DLC deposition description of the report
    status: ground
    source: miyoshi1997
    where: Experimental section, DLC deposition paragraph
  - benchmark: surface_roughness_rms
    label: Mean surface roughness (rms), ion-beam DLC at 1500 eV
    value: 22
    unit: nm
    scope: material
    conditions:
      film: ion-beam-deposited DLC at 1500 eV ion energy
    method: Surface characterisation as reported
    status: ground
    note: The 700 eV film is 14 nm rms in the same section.
    source: miyoshi1997
    where: Results, DLC film characterisation paragraph
corrosion:
  - environment: Oxygen plasma (laboratory), which the paper links to atomic-oxygen erosion in orbit
    headline: In a short oxygen-plasma test, the hexane-deposited DLC film was etched and lost hardness.
    effect: The paper reports a corrosion rate of 434 ± 26 Å/min for DLC and a fall in hardness from 9.1 GPa to 6.3 GPa after exposure. The paper's aim, from its title, is protection by a silicon-oxide top layer (SiOx-DLC) on the DLC film.
    rating: moderate
    conditions:
      exposure: oxygen plasma, 12 sccm, RF 13.5 MHz, 10 W, bias -179 V, 22 min
      film: DLC from hexane by PECVD
      test: laboratory plasma only; no flight result
    source: ferreira2021
    where: Section 2 (corrosion conditions), Table 2 and Table 4
  - environment: Air at high temperature (maximum temperature rated by NACL)
    headline: NACL rates its DLC at a maximum working temperature of 500 °C, but prints no test.
    effect: The NACL sheet gives 500 °C as the maximum working temperature, with no test or formulation stated. No oxidation onset or ageing data were found in the sources held for this run.
    rating: unknown
    conditions:
      basis: manufacturer rating, not measured in these sources
    source: nacl-dlc-tds
    where: Page 2, row 'Max. Working Temp.'
  - environment: Humidity and salt spray (military test methods listed by NACL)
    headline: NACL says its DLC is approved against named military test methods but prints no results.
    effect: The NACL data sheet lists humidity, salt spray and adhesion tests under military specifications. It gives no numbers for those tests, so no corrosion rating is assigned from this source.
    rating: unknown
    conditions:
      basis: manufacturer statement; no results printed
    source: nacl-dlc-tds
    where: Page 1, text on military specifications; page 2 test list
risks:
  hazards:
    - text: 'PubChem''s element record for carbon lists ''H319 (55.1%): Causes serious eye irritation'' and ''H335 (51.1%): May cause respiratory irritation'', both from company notifications. PubChem does not say which carbon form each notification describes, so this is a proxy for DLC and not a classification of the coating.'
      ghs:
        - H319
        - H335
      source: pubchem-carbon
      where: Safety and Hazards, GHS Classification and Hazard Classes and Categories (CID 5462310)
    - text: PubChem's carbon record also states that the chemical 'does not meet GHS hazard criteria' for a share of reports. Toxicity data for DLC coatings were not found in any source held for this run.
      ghs: []
      source: pubchem-carbon
      where: Safety and Hazards, GHS Classification note
  failure_risks:
    - mode: Adhesion loss (delamination) under scratch loading
      trigger: Scratch test with normal load rising from 0.2 N to 30 N
      consequence: The paper's first critical load LC1 for the hexane-deposited DLC film is 11.2 N (printed as 11.2 ± 1.8 N).
      severity: moderate
      source: ferreira2021
      where: Section 3 (Adhesion)
    - mode: Friction rise after oxygen corrosion
      trigger: Oxygen-plasma corrosion of DLC, as cited by Ferreira et al. from Tagawa et al.
      consequence: The paper quotes 'the DLC films present a high friction coefficient (0.38)' after oxygen corrosion, and says friction later returned to 0.05.
      severity: moderate
      source: ferreira2021
      where: Section 3, values from other cited work
    - mode: Erosion in oxygen plasma, which the paper links to atomic oxygen
      trigger: Oxygen plasma exposure, 22 min in the laboratory test
      consequence: The DLC film was etched at 434 ± 26 Å/min and its hardness fell to 6.3 GPa (printed 6.3 ± 1.8 GPa).
      severity: moderate
      source: ferreira2021
      where: Table 2 and Table 4
  handling:
    - text: No DLC-specific safety data sheet was found. The hazard entries above use the carbon element record, which PubChem aggregates from notifiers.
      source: pubchem-carbon
      where: Safety and Hazards (CID 5462310)
  mitigations:
    - text: The paper's answer to oxygen-plasma erosion is a silicon-oxide top layer (SiOx-DLC) on the DLC film, which the title describes as protection against atomic oxygen and ozone. This was not tested in orbit.
      source: ferreira2021
      where: Title; Sections 1 and 4
uses:
  - application: mechanisms
    device: Engine components such as fuel injection systems, valve trains and pistons
    example: Oerlikon says its DLC coating provides excellent protection against abrasion, tribo-oxidation and adhesive wear and gives low friction losses in high-speed sliding.
    source: oerlikon-balinit-product
    where: BALINIT DLC product page, application and performance text
  - application: mechanisms
    device: Locating and positioning pins for aluminium die-cast body parts
    example: Misumi's DLC locating pin datasheet gives a body-shell test on aluminium die-cast parts, with a cycle count printed in its test results table.
    source: misumi-dlc
    where: Test results section (installation location Body in White)
  - application: optics-and-cameras
    device: Barcode scanner windows, laser optics, optical mirrors and infrared windows
    example: NACL lists these as typical applications for its DLC coating, which it says is deposited at or near room temperature.
    source: nacl-dlc-tds
    where: Page 1, 'Ideal Diamond-Like Carbon Applications' and deposition text
supply:
  - subject: Graphite (carbon context; not the DLC precursor)
    producers:
      - country: China
        share_percent: 82
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (page lists 'Graphite')
        listed: true
    recycling: 'USGS: the abundance of graphite in the world market inhibits increased recycling efforts; information on recycled quantity was not available.'
    substitutes:
      - 'USGS: molybdenum disulfide competes as a dry lubricant but is more sensitive to oxidizing conditions.'
    source: usgs-mcs2026-graphite
    where: Text on China's production share, Recycling and Substitutes sections; World Mine Production table (2025e)
media: []
documents:
  - title: North American Coating Laboratories, Diamond-Like Carbon Coating Technical Data Sheet
    type: datasheet
    url: https://www.nacl.com/wp-content/uploads/2016/05/DLC-TDS.pdf
  - title: MISUMI DLC coating datasheet (January 2026)
    type: datasheet
    url: https://uk.misumi-ec.com/files/images/products/docs/misumi_dlc-datasheet-en.pdf
    year: 2026
  - title: SiOx Top Layer on DLC Films for Atomic Oxygen and Ozone Corrosion Protection in Aerospace Applications (Materials Research, open access)
    type: paper
    url: https://scielo.br/j/mr/a/3JnHb7KV4tDcPmbQsRqSYWm/?lang=en
    year: 2021
  - title: Structure, stability and stress properties of amorphous and nanostructured carbon films (arXiv cond-mat/0605381)
    type: paper
    url: https://arxiv.org/pdf/cond-mat/0605381
    year: 2006
  - title: 'NASA: Lubrication by Diamond and Diamondlike Carbon Coatings (E-10462)'
    type: report
    url: https://ntrs.nasa.gov/citations/19970025138
    year: 1997
  - title: 'USGS Mineral Commodity Summaries 2026: Graphite (Natural)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf
    year: 2026
  - title: 'PubChem compound record: Carbon (CID 5462310), Safety and Hazards'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/5462310
    year: 2026
gaps:
  - No flight, vacuum-exposure or outgassing result for DLC was found in this run. The only space-related source is the 1997 NASA ultrahigh-vacuum friction study on laboratory films, and it gives no mass-loss or outgassing data.
  - No orbital atomic-oxygen erosion yield for DLC was found. The corrosion rate recorded above is from a laboratory oxygen plasma and is not comparable to an orbital yield.
  - Wear rates in the NASA report are printed with exponents, so they are left out.
  - The density recorded is a simulation result (Fyta et al.). No measured bulk density for a ta-C or a-C:H film was found in an open source in this run.
  - The Oerlikon BALINIT DLC specification table (hardness HIT, dry friction, maximum service and process temperature) was read in this run, but the cited page's raw text does not contain it, so those rows are left out of the file. No second source for that grade was found.
  - Misumi prints the hardness as '~ 2.000' with a dot as thousands separator, and prints the friction range as '0.15 - 2'. Neither can be recorded as a checked number, so both are left out.
  - The NACL refractive index and hardness are ranges that depend on formulation; no single value is recorded.
  - Hydrogen content printed as H (%) in Table 4 of the Ferreira paper is not defined in the extract, so it is left out.
  - The supply row is graphite, shown as carbon context. The hydrocarbon precursors actually used (methane in the NASA report, hexane in the Ferreira paper) were not sourced for supply in this run.
  - The EU critical raw materials list was not checked for graphite in this run.
  - Property names for hardness, friction, coating thickness, roughness, deposition and process temperature are not in spores/property-canon.yaml; snake_case names are used.
  - No DLC-specific safety data sheet was found. Hazard entries use PubChem's carbon element record, which does not name the carbon form.
  - The Ferreira paper's abstract and Section 3 give different critical loads for the same DLC film. Only the LC1 value from Section 3 is recorded.
  - Wikipedia is cited for the definition and history only; no numbers were taken from it.
sources:
  oerlikon-balinit-product:
    title: BALINIT DLC product page (Oerlikon Balzers)
    id: Oerlikon Balzers BALINIT DLC
    url: https://oerlikon.com/balzers/be/en/portfolio/balzers-surface-solutions/pvd-and-pacvd-based-coating-solutions/balinit/carbon-dlc-based/balinit-dlc
    kind: web
    license: manufacturer web page, cited not reproduced
  nacl-dlc-tds:
    title: North American Coating Laboratories, Diamond-Like Carbon Coating Technical Data Sheet
    id: NACL DLC data sheet (PDF)
    url: https://www.nacl.com/wp-content/uploads/2016/05/DLC-TDS.pdf
    kind: datasheet
    license: manufacturer data sheet, cited not reproduced
  misumi-dlc:
    title: MISUMI Europa GmbH, DLC coating datasheet
    id: MISUMI DLC datasheet, January 2026
    url: https://uk.misumi-ec.com/files/images/products/docs/misumi_dlc-datasheet-en.pdf
    kind: datasheet
    license: supplier datasheet, cited not reproduced
  ferreira2021:
    title: SiOx Top Layer on DLC Films for Atomic Oxygen and Ozone Corrosion Protection in Aerospace Applications
    id: doi:10.1590/1980-5373-MR-2020-0511 (Materials Research 24(3), 2021)
    url: https://scielo.br/j/mr/a/3JnHb7KV4tDcPmbQsRqSYWm/?lang=en
    kind: paper
    license: CC BY 4.0
  fyta2006:
    title: Structure, stability and stress properties of amorphous and nanostructured carbon films
    id: arXiv cond-mat/0605381
    url: https://arxiv.org/pdf/cond-mat/0605381
    kind: paper
    license: arXiv preprint, licence as listed on arXiv
  miyoshi1997:
    title: Lubrication by Diamond and Diamondlike Carbon Coatings (NASA Lewis, report E-10462)
    id: NTRS 19970025138
    url: https://ntrs.nasa.gov/citations/19970025138
    kind: report
    license: public domain (NASA)
  usgs-mcs2026-graphite:
    title: Mineral Commodity Summaries 2026, Graphite (Natural)
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    kind: web
    license: public domain (USGS)
  pubchem-carbon:
    title: PubChem compound record, Carbon (CID 5462310)
    id: CID 5462310
    url: https://pubchem.ncbi.nlm.nih.gov/compound/5462310
    kind: database
    license: public domain (NCBI)
  wikipedia-dlc:
    title: 'Wikipedia: Diamond-like carbon (definition and history only)'
    id: en.wikipedia.org
    url: https://en.wikipedia.org/wiki/Diamond-like_carbon
    kind: web
    license: CC BY-SA 4.0
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 18
  unreachable: 1
  caveats: 3
  note: 'Read by an AI assistant on 2026-11-01 from the pages and PDFs named in each entry. Unreachable: the PMC review (PMC7878482) returned a verification page and could not be read. Caveats: the NACL maximum temperature has no test; the Fyta density is a simulation; the Ferreira critical loads differ between abstract and text. The Oerlikon BALINIT DLC table was read but is not in the file because the cited raw page does not contain it.'
story:
  recipe:
    line: Diamond-like carbon is made of carbon alone in most grades, and some grades add hydrogen. The atoms form a disordered network with a mix of diamond-type sp3 bonds and graphite-type sp2 bonds. It is deposited as a thin film by physical vapour deposition (PVD) or by plasma-enhanced chemical vapour deposition (PECVD) from a hydrocarbon gas or liquid.
    parts:
      - name: Carbon
        symbol: C
        role: The whole film. Its sp3 bonds give the hardness, and its sp2 bonds give a softer, graphite-like part of the network.
      - name: Hydrogen
        symbol: H
        role: Present in hydrogenated grades (a-C:H). Misumi lists its Ta-C coating as hydrogen-free.
  risk_groups:
    - title: For people
      level: 0
      verdict: No DLC data sheet found; carbon record flags irritation
      lead: No DLC-specific safety data sheet was found. The hazard entries come from PubChem's record for the element carbon, which lists eye and respiratory irritation from company notifications.
      points:
        - label: Eye and airway
          line: 'PubChem''s carbon record lists ''H319 (55.1%): Causes serious eye irritation'' and ''H335 (51.1%): May cause respiratory irritation''. These come from company notifications, not from a test of a DLC coating.'
    - title: In a plasma or a fire
      level: 0
      verdict: Oxygen plasma etches the film in the lab
      lead: Oxygen plasma is a process hazard for the film, not for people.
      points:
        - label: Erosion
          line: In a laboratory oxygen plasma, the hexane-deposited DLC film etched at 434 ± 26 Å/min. This shows how the film wears in reactive oxygen, but it is not a flight result.
  why: 'Diamond-like carbon (DLC) is a coating, not a bulk material, and it is chosen for hardness and low friction on sliding parts and optics. The grades in these sources are made and rated differently, so the numbers are not interchangeable: a PECVD film measured in one lab study, and a manufacturer optical DLC data sheet that rates the coating for 500 °C.'
  uses:
    - where: Engine and sliding parts
      line: Oerlikon says its BALINIT DLC coating suits engine components such as fuel injection systems, valve trains and pistons, where it protects against abrasion and adhesive wear.
    - where: Locating pins for aluminium parts
      line: Misumi sells a DLC-coated locating pin for positioning aluminium die-cast body parts. Its datasheet prints a cycle count from a body-shell test.
    - where: Optics
      line: NACL lists barcode scanner windows, laser optics, optical mirrors and infrared windows as typical DLC applications.
  can_do:
    - label: Hardness
      line: Resist abrasion on sliding parts. NACL rates its DLC at a Vickers hardness of 1000 to 3000 HV, depending on formulation.
    - label: Friction
      line: Keep friction low. NACL lists the as-deposited DLC at a friction below 0.1, with no test method printed.
    - label: Temperature
      line: Run at up to 500 °C by NACL's rating. No test is printed for that figure.
    - label: Deposition
      line: Coat without heating the part much. NACL says its DLC is deposited below 50 °C.
  compare: DLC is a thin, hard, low-friction film on a part, not a bulk material. The NACL sheet rates hardness at 1000 to 3000 HV and friction below 0.1 for the as-deposited film, with a maximum working temperature of 500 °C. The laboratory PECVD film measured 9.1 GPa hardness and a 79 GPa modulus, and its erosion in oxygen plasma (434 Å/min) is the weak point in the lab data. The compare rows use the three properties that the sources report for DLC.
  compare_rows:
    - label: Hardness (Vickers) of the NACL DLC coating
      benchmark: hardness_vickers
    - label: Friction coefficient of the NACL DLC coating (as-deposited)
      benchmark: friction_coefficient
    - label: Maximum working temperature of the NACL DLC coating
      benchmark: max_service_temp
  handling:
    - No DLC-specific safety data sheet was found. The carbon element record lists eye and respiratory irritation from company notifications.
    - The sources do not give a cleaning or handling method for coated parts.
  good_for:
    - Hard sliding surfaces. NACL rates its DLC at 1000 to 3000 HV, depending on formulation.
    - Coating parts without much heat. NACL deposits its DLC below 50 °C.
    - Optical windows and mirrors that need a scratch-resistant, low-friction surface, as NACL describes its coating.
  watch_out:
    - Oxygen plasma erodes the film. The PECVD DLC etched at 434 ± 26 Å/min in the laboratory and lost hardness.
    - The 500 °C maximum temperature rests on one manufacturer rating with no test printed. Check it for the grade you buy.
    - No orbital erosion or outgassing data were found. The only space-related study is a 1997 ultrahigh-vacuum friction test on laboratory films.
  verdict: Diamond-like carbon is a hard, low-friction coating for sliding parts and optics. The NACL data sheet rates its hardness at 1000 to 3000 HV and its maximum working temperature at 500 °C, but no test is printed. The laboratory PECVD film has 9.1 GPa hardness and erodes in oxygen plasma, and no orbital erosion or outgassing data were found.