{
  "spore": "profile",
  "id": "titanium-nitride",
  "spore_version": "0.2",
  "family": "carbide-nitride-boride-ceramics",
  "name": "Titanium nitride",
  "abbreviation": "TiN",
  "role": "hard, golden-coloured ceramic coating and bulk ceramic (nitride)",
  "category": "ceramics",
  "type": "nitrides",
  "summary": "Titanium nitride is a rock-salt ceramic that is very hard, has a melting point above 2900 degC and conducts electricity like a metal. Yu et al. (2014) compute a bulk modulus of 317 GPa, a shear modulus of 202 GPa and a Vickers hardness of 23.39 GPa for the rock-salt phase at zero pressure, and the experimental bulk modulus they quote is 320 GPa. Goel et al. (2025) measured a thermal conductivity of 26.96 W/(m K) for an 86 nm plasma-enhanced ALD film and 7.01 W/(m K) for a thermal ALD film of the same thickness, and an electrical resistivity of 0.000091 Ohm cm for a film grown at 400 degC. Cathodic-arc films annealed in air began to form rutile above 600 degC and were fully rutile above 700 degC (Chen et al., AVS 2004).\n",
  "best_for": "Hard, wear-resistant thin coatings on tools and sliding parts, and other uses where a melting point above 2900 degC and metal-like conduction both matter",
  "weakest_at": "Oxidation in air above about 600 degC, where the surface converts to rutile titanium dioxide (AVS 2004), and friction rise after long exposure outside a spacecraft (JAXA, ISS exposure)",
  "identity": {
    "formula": "TiN",
    "cas": "25583-20-4",
    "crystal_system": "cubic",
    "space_group": "Fm-3m",
    "designations": [],
    "source": "yu2014",
    "where": "Table 1, TiN row (rock-salt structure, Fm3 with a bar over the 3, printed as Fm-3m here); CAS number from the PubChem record for CID 93091, which names titanium nitride as CAS Reg. No. 25583-20-4"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "extreme-heat"
    ],
    "applications": [
      "mechanisms",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "melting_point",
      "value": 2900,
      "bound": "lower",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "basis": "stated as exceeding 2900 degC; no measurement method given"
      },
      "method": "Statement in the introduction of an open-access paper",
      "status": "ground",
      "source": "goel2025",
      "where": "Introduction, paragraph 1 (sentence beginning with the high melting temperature of TiN)",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Mechanical hardness quoted in a paper",
      "value": 20,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "stated without test method, load or film orientation"
      },
      "method": "Value stated in the introduction of an open-access paper, which cites earlier work for it",
      "status": "ground",
      "source": "goel2025",
      "where": "Introduction, paragraph 1 (exceptional mechanical hardness, 20 GPa)",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "vickers_hardness",
      "label": "Vickers hardness, rock-salt TiN (calculated)",
      "value": 23.39,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results"
      },
      "method": "Calculated by Yu et al. from the Pugh ratio and shear modulus using the Chen model; a model value, not a measured hardness",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (Hv column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "bulk_modulus",
      "label": "Bulk modulus, rock-salt TiN (calculated)",
      "value": 317,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results, Voigt-Reuss-Hill approximation"
      },
      "method": "First-principles calculation (DFT, GGA and LDA) in an open-access paper",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (B column); text in section 3.3",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "bulk_modulus",
      "label": "Bulk modulus, rock-salt TiN (experimental value quoted)",
      "value": 320,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "experimental value listed for comparison, from the reference the paper calls 46"
      },
      "method": "Experimental value quoted in the paper's comparison row (Exp[46])",
      "status": "ground",
      "source": "yu2014",
      "where": "Table 1, TiN row, Exp[46] line (B column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "shear_modulus",
      "label": "Shear modulus, rock-salt TiN (calculated)",
      "value": 202,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results"
      },
      "method": "First-principles calculation with Voigt-Reuss-Hill averaging",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (G column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Young's modulus, rock-salt TiN (calculated)",
      "value": 500,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results"
      },
      "method": "First-principles calculation with Voigt-Reuss-Hill averaging",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (E column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "poissons_ratio",
      "value": 0.237,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results"
      },
      "method": "First-principles calculation with Voigt-Reuss-Hill averaging",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (nu column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "elastic_constant_c44",
      "label": "Elastic constant C44, rock-salt TiN (experimental value quoted)",
      "value": 163,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "experimental value listed for comparison, from the reference the paper calls 46"
      },
      "method": "Experimental value quoted in the paper's comparison row (Exp[46])",
      "status": "ground",
      "source": "yu2014",
      "where": "Table 1, TiN row, Exp[46] line (C44 column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "elastic_constant_c44",
      "label": "Elastic constant C44, rock-salt TiN (calculated)",
      "value": 176,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "basis": "0 GPa, rock-salt TiN, average of GGA and LDA results"
      },
      "method": "First-principles calculation from stress-strain relations",
      "status": "calculated",
      "source": "yu2014",
      "where": "Table 1, TiN row, Ave line (C44 column)",
      "source_detail": {
        "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
        "id": "arXiv:1411.1485",
        "url": "https://arxiv.org/pdf/1411.1485",
        "year": 2014,
        "kind": "paper",
        "license": "arXiv preprint (author license as listed on arXiv)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 86 nm plasma-enhanced ALD film",
      "value": 26.96,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "form": "86 nm TiN thin film, plasma-enhanced ALD",
        "method_of_measurement": "thin film laser flash analyzer (TF-LFA)",
        "temperature": "room temperature (not stated more precisely in the paper)"
      },
      "method": "Laser flash measurement on a thin film, reported in an open-access paper",
      "status": "ground",
      "source": "goel2025",
      "where": "Abstract; Section 2.3 (Thermal properties)",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, 86 nm thermal ALD film",
      "value": 7.01,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "form": "86 nm TiN thin film, thermal ALD",
        "method_of_measurement": "thin film laser flash analyzer (TF-LFA)",
        "temperature": "room temperature (not stated more precisely in the paper)"
      },
      "method": "Laser flash measurement on a thin film, reported in an open-access paper",
      "status": "ground",
      "note": "The paper says the thermal ALD film conducts heat much less well than the plasma-enhanced film of the same thickness.",
      "source": "goel2025",
      "where": "Abstract; Section 2.3 (Thermal properties)",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, plasma-enhanced ALD film grown at 400 degC",
      "value": 0.000091,
      "bound": "exact",
      "unit": "Ohm cm",
      "scope": "material",
      "conditions": {
        "process": "plasma-enhanced ALD of TiN from TiCl4 and NH3 at 400 degC growth temperature",
        "unit_in_source": "0.91 × 10-4 Ohm cm, written here as a plain decimal"
      },
      "method": "Value stated in the results of an open-access paper, derived from the measured conductivity",
      "status": "ground",
      "source": "goel2025",
      "where": "Section 2.2 (electrical transport, text on growth temperature and resistivity); Figure 5f",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, plasma-enhanced ALD film grown at 200 degC",
      "value": 0.00297,
      "bound": "exact",
      "unit": "Ohm cm",
      "scope": "material",
      "conditions": {
        "process": "plasma-enhanced ALD of TiN from TiCl4 and NH3 at 200 degC growth temperature",
        "unit_in_source": "29.7 × 10-4 Ohm cm, written here as a plain decimal"
      },
      "method": "Value stated in the results of an open-access paper, derived from the measured conductivity",
      "status": "ground",
      "source": "goel2025",
      "where": "Section 2.2 (electrical transport, text on growth temperature and resistivity); Figure 5f",
      "source_detail": {
        "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
        "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
        "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
        "year": 2025,
        "kind": "paper",
        "license": "CC BY 3.0 (per the article page)"
      }
    },
    {
      "benchmark": "oxidation_onset_temperature",
      "label": "Temperature at which rutile first appears in air",
      "value": 600,
      "bound": "lower",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "atmosphere": "static air",
        "treatment": "2 h anneal at each temperature from 500 to 800 degC",
        "film": "cathodic-arc deposited TiN film, columnar structure"
      },
      "method": "XRD and Raman spectroscopy after the anneal; rutile identified above 600 degC",
      "status": "ground",
      "note": "A conference poster. The 550 degC and 640 degC onsets found in other searches are from other sample forms and methods and are not used here.",
      "source": "avs2004",
      "where": "Abstract (paper SE-TuP5)",
      "source_detail": {
        "title": "Oxidation Behavior of Titanium Nitride Films (H.-Y. Chen et al.), AVS 51st International Symposium, paper SE-TuP5",
        "id": "AVS 51st International Symposium, 16 November 2004",
        "url": "https://www2.avs.org/symposium2004/Papers/Paper_SE-TuP5.html",
        "year": 2004,
        "kind": "web",
        "license": "conference abstract (cited)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Static air at 500 to 800 degC (2 h anneals of TiN films)",
      "headline": "Above about 600 degC the TiN surface converts to rutile titanium dioxide, and above 700 degC the film is fully rutile.",
      "effect": "XRD and Raman spectra of cathodic-arc TiN films annealed in static air showed rutile TiO2 from 600 degC, with its intensity rising quickly with temperature. The films were completely oxidized to rutile above 700 degC. The as-deposited films were columnar and an oxide layer appeared on top of the columns.",
      "rating": "moderate",
      "conditions": {
        "exposure": "static air, 2 h at each temperature from 500 to 800 degC",
        "film": "cathodic-arc deposited TiN"
      },
      "source": "avs2004",
      "where": "Abstract (paper SE-TuP5)"
    },
    {
      "environment": "Low Earth orbit on the outside of the ISS Service Module (MPAC&SEED exposure, 1 to 3 years)",
      "headline": "Outside the ISS, the TiN coating's friction rose after three years, while a MoS2 coating stayed low.",
      "effect": "XPS and depth profiles of TiN-coated stainless steel after exposure showed a titanium oxide layer (TiOx) formed during film preparation and a silicon and oxygen layer at the surface. The authors suggest that silicon from silicone adhesives used on the station reacted with atomic oxygen to form SiO2. The friction coefficient rose strongly for TiN after three years in orbit, and the authors say the surface contamination layer may explain the change in tribological behaviour.",
      "rating": "moderate",
      "conditions": {
        "exposure": "ISS Service Module exterior, one, two and three years, followed by vacuum annealing and vacuum friction tests",
        "atmosphere": "orbital atomic oxygen, space radiation, thermal cycling (as described by the authors)",
        "substrate": "SUS304 stainless steel with a TiN coating"
      },
      "source": "jaxa2008",
      "where": "Sections 3.1 (friction) and 3.2 (surface analyses); Conclusion"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem aggregates GHS notifications for titanium nitride (CID 93091, 57 reports from 6 notifications): 33.3% (19 of 57) do not meet GHS hazard criteria.",
        "ghs": [
          "H228 (61.4% of reports): Flammable solid",
          "H315 (19.3% of reports): Causes skin irritation"
        ],
        "source": "pubchem-tin",
        "where": "Safety and Hazards, GHS Classification (CID 93091 record)"
      },
      {
        "text": "PubChem summary of an Alfa Aesar safety data sheet: 'May cause irritation.' No other hazard statement is given in that summary.",
        "ghs": [],
        "source": "pubchem-tin",
        "where": "Safety and Hazards, Hazards Summary (CID 93091 record)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Surface oxidation to rutile in hot air",
        "trigger": "Heating in static air above about 600 degC",
        "consequence": "The surface converts to rutile titanium dioxide, and above 700 degC the film is fully rutile.",
        "severity": "moderate",
        "source": "avs2004",
        "where": "Abstract (paper SE-TuP5)"
      },
      {
        "mode": "Friction rise on a sliding coating after long exposure outside the ISS",
        "trigger": "One to three years of exposure on the ISS Service Module, then friction tests in vacuum after vacuum annealing",
        "consequence": "After three years the TiN-coated stainless steel showed a large increase in friction coefficient, in the same group as bare SUS304 steel and the copper coating.",
        "severity": "moderate",
        "source": "jaxa2008",
        "where": "Section 3.1 (friction)"
      }
    ],
    "side_effects": [
      {
        "text": "A silicon and oxygen layer, which the authors attribute to silicone adhesives on the station, formed on the exposed TiN surface and may change its friction.",
        "affects": "Surface friction of a TiN-coated sliding part",
        "source": "jaxa2008",
        "where": "Section 3.2 (surface analyses) and Conclusion"
      }
    ],
    "handling": [
      {
        "text": "In the deposition process, the samples were kept in the load lock for 20 minutes to cool before removal, to prevent oxidation.",
        "source": "goel2025",
        "where": "Experimental section, text after the deposition conditions"
      },
      {
        "text": "PubChem gives no handling or storage advice for titanium nitride; check the safety data sheet from your supplier for powder, target or coating material.",
        "source": "pubchem-tin",
        "where": "Safety and Hazards (CID 93091 record)"
      }
    ],
    "mitigations": [
      {
        "text": "A MoS2 coating on the same stainless steel kept its friction low after three years in orbit, where the TiN coating did not.",
        "source": "jaxa2008",
        "where": "Section 3.1 (friction)"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Lubricative coating on sliding parts of the ISS Service Module (MPAC&SEED exposure test)",
      "example": "TiN-coated stainless steel was flown outside the ISS for one to three years. It kept friction almost low after one year, but its friction rose after three years in orbit.",
      "source": "jaxa2008",
      "where": "Abstract; Section 3.1 (friction)"
    },
    {
      "application": "structures",
      "device": "Protective hard coating on cutting tools and high-stress parts (terrestrial)",
      "example": "The paper calls TiN a protective coating for cutting tools and high-stress environments, where durability and stability are important.",
      "source": "goel2025",
      "where": "Introduction, paragraph 1"
    }
  ],
  "supply": [
    {
      "subject": "Titanium (the metal in TiN; nitrogen is not covered by this source)",
      "producers": [
        {
          "country": "China",
          "share_percent": 70.3,
          "year": 2025
        },
        {
          "country": "Japan",
          "share_percent": 14.3,
          "year": 2025
        },
        {
          "country": "Russia",
          "share_percent": 6.8,
          "year": 2025
        },
        {
          "country": "Kazakhstan",
          "share_percent": 4.3,
          "year": 2025
        },
        {
          "country": "Saudi Arabia",
          "share_percent": 3.2,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: owing to limited survey responses, consumption data for titanium scrap in the titanium metal industry were withheld.",
      "substitutes": [],
      "source": "usgs-mcs2026-titanium",
      "where": "World Sponge Metal Production table, 2025e (China 260,000 t, Japan 53,000 t, Russia 25,000 t, Kazakhstan 16,000 t, Saudi Arabia 12,000 t; world total 370,000 t, rounded; shares calculated by Space Mushroom against that total). Import Sources (2021 to 2024): sponge metal, Japan 77%. The United States did not produce sponge in 2025."
    }
  ],
  "media": [],
  "documents": [],
  "gaps": [
    "Density not found: no measured or calculated density for TiN was read in a fetched page in this run.",
    "Coefficient of thermal expansion not found in a fetched page; the only figure seen was in Wikipedia, which this brief limits to composition and history.",
    "Lattice constant not found in a fetched page (Fodil et al. 2014 is open access, but its full text did not load).",
    "Thermogravimetric oxidation onset in air for dense TiN not found in an open source; the MDPI Coatings and RSC pages returned access denied. The AVS 2004 poster is the only oxidation value used.",
    "Nitrogen supply and abundance not sourced in this run; supply covers the titanium component only.",
    "Titanium's status on the USGS 2025 critical minerals list and the EU critical raw materials list was not read in this run (the USGS critical-minerals page did not load and the MCS text has no list statement). critical_lists is left empty.",
    "Atomic weights of titanium and nitrogen were not read in a fetched page, so the recipe parts have no atomic_weight.",
    "Hardness method and load are not stated in the open paper that quotes 20 GPa, so that value is kept as a ground value without a method.",
    "Property names used here that are not in spores/property-canon.yaml: hardness, vickers_hardness, elastic_constant_c44, oxidation_onset_temperature.",
    "Calculated elastic and hardness values are zero-kelvin, zero-pressure DFT results, not measured film or bulk data; only the rows marked Exp[46] are experimental.",
    "No flight or radiation test of a TiN-based coating beyond the JAXA ISS exposure was found; the JAXA paper is a Japanese symposium paper with a single coating set.",
    "The Kozma et al. 2020 review (spread in TiN property data) was listed by search but its PDF did not load.",
    "No media images were added."
  ],
  "story": {
    "why": "Titanium nitride is a rock-salt ceramic. It is hard and has a high melting point, and it conducts electricity like a metal. It appears golden when deposited as a coating. The rock-salt structure and the strong titanium-nitrogen bonds explain the hardness that the calculations and papers in this file report. The same bonding also means the film tends to oxidise at the surface when it is heated in air, which is the main limit on its use.",
    "uses": [
      {
        "where": "Hard coatings on tools and high-stress parts",
        "line": "The 2025 paper describes titanium nitride as a protective coating for cutting tools and high-stress environments."
      },
      {
        "where": "Lubricative coating on the outside of the ISS",
        "line": "A JAXA exposure test flew TiN-coated stainless steel on the outside of the ISS for one to three years. The coating kept friction low after one year but its friction rose after three years in orbit."
      }
    ],
    "can_do": [
      {
        "label": "Hardness",
        "line": "A first-principles calculation gives a Vickers hardness of 23.39 GPa for rock-salt TiN at zero pressure. A quoted value for mechanical hardness is 20 GPa. These are model and quoted values, not a film test.",
        "benchmark": "vickers_hardness",
        "scope": "material",
        "value": "23.39 GPa"
      },
      {
        "label": "Stiffness",
        "line": "The same calculation gives a Young's modulus of 500 GPa, a shear modulus of 202 GPa and a bulk modulus of 317 GPa. The experimental bulk modulus quoted in the paper is 320 GPa.",
        "benchmark": "elastic_modulus",
        "scope": "material",
        "value": "500 GPa"
      },
      {
        "label": "Melting",
        "line": "The introduction of the 2025 paper says titanium nitride melts above 2900 degC. The paper does not give a measured value.",
        "benchmark": "melting_point",
        "scope": "material",
        "value": "Above 2900 degC"
      },
      {
        "label": "Thermal conduction",
        "line": "A plasma-enhanced ALD film of 86 nm reached 26.96 W/(m·K), and a thermal ALD film of the same thickness reached 7.01 W/(m·K). The paper calls the thermal conductivity of TiN moderate rather than exceptionally high.",
        "benchmark": "thermal_conductivity",
        "scope": "material",
        "value": "26.96 W/(m·K)"
      },
      {
        "label": "Electrical resistivity",
        "line": "Plasma-enhanced ALD films grown at 400 degC had a resistivity of 0.91 × 10-4 Ohm cm. The same process at 200 degC gave 29.7 × 10-4 Ohm cm, so growth temperature matters a great deal.",
        "benchmark": "electrical_resistivity",
        "scope": "material",
        "value": "0.000091 Ohm cm"
      }
    ],
    "compare": "Titanium nitride sits in the hard-ceramic group. Its melting point and hardness are high, and its bulk modulus is close to the experimental value the paper quotes. Its weak point is oxidation in air above about 600 degC, where the surface turns to rutile. It also conducts electricity, unlike most ceramics, so it is used as a coating where that matters.",
    "compare_rows": [
      {
        "label": "Melting point",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Bulk modulus",
        "benchmark": "bulk_modulus",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "The safety data sheet is not summarised in PubChem for this material. Read the supplier's sheet for powder, target or coating stock.",
      "Cool films in a vacuum load lock before exposing them to air.",
      "Keep heating in air below about 600 degC if the surface must stay TiN.",
      "Some reports classify the material as a flammable solid, so keep powder away from heat sources."
    ],
    "good_for": [
      "Hardness and wear. The calculated Vickers hardness of 23.39 GPa is in the range of the 20 GPa value quoted in the 2025 paper.",
      "Metal-like conduction in a hard ceramic. The 2025 paper measured an electrical resistivity of 0.000091 Ohm cm for a film grown at 400 degC."
    ],
    "watch_out": [
      "Oxidation in air. Films form rutile above about 600 degC and are fully rutile above 700 degC.",
      "Friction rise after long exposure in orbit. TiN friction rose after three years on the ISS while MoS2 stayed low.",
      "Thermal conductivity depends strongly on how the film is grown. The two films of the same thickness differed by almost four times."
    ],
    "verdict": "Titanium nitride is a strong, hard coating that conducts electricity. It should not be used in hot air above about 600 degC without a protective layer, and it needs a space-exposure check before flight.",
    "recipe": {
      "line": "Titanium nitride is one titanium atom bonded to one nitrogen atom in a rock-salt crystal. It is made in thin-film form by vapour-phase deposition: the thin-film paper grows it from titanium tetrachloride (TiCl4) and ammonia (NH3) by atomic layer deposition.",
      "parts": [
        {
          "name": "Titanium",
          "symbol": "Ti",
          "role": "The metal that gives the film its hardness and its metallic conduction; it forms rock-salt TiN with nitrogen and some TiO2 with oxygen."
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "Fills the other sub-lattice of the rock-salt structure and gives the bonds their strong covalent character."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "Titanium nitride is not classified hazardous by most reporters to PubChem. Some reports classify the material as a flammable solid and as a skin irritant.",
        "points": [
          {
            "label": "The notifications",
            "line": "PubChem records 57 reports from 6 notifications. 33.3% of them (19 of 57) do not meet GHS hazard criteria. The rest carry H228 (flammable solid, 61.4%) and H315 (skin irritation, 19.3%)."
          },
          {
            "label": "Summary",
            "line": "The PubChem summary of an Alfa Aesar data sheet says the material 'may cause irritation'."
          }
        ],
        "level": 0,
        "verdict": "Not classified as hazardous by most reporters"
      },
      {
        "title": "If the coating is heated in air",
        "lead": "These results come from laboratory anneals of films in static air, not from field incidents.",
        "points": [
          {
            "label": "Rutile forms",
            "line": "Films annealed in air for 2 hours began to form rutile titanium dioxide above 600 degC and were fully rutile above 700 degC."
          }
        ]
      },
      {
        "title": "Handling",
        "points": [
          {
            "label": "Cooling",
            "line": "After deposition, the films were held in the load lock for 20 minutes to cool before they were removed, to prevent oxidation."
          }
        ]
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 15,
    "unreachable": 3,
    "caveats": 2,
    "note": "Written by an AI assistant on 2026-10-26 from pages read in this run. Three open sources could not be read (MDPI Coatings 14(7) 823, RSC Materials Advances 2024 d3ma00965c, and the Kozma et al. 2020 review) because the site denied access or returned an HTML page. Calculated values are DFT results at 0 GPa."
  },
  "sources": {
    "pubchem-tin": {
      "title": "PubChem compound record CID 93091 (titanium mononitride, TiN; CAS Reg. No. 25583-20-4 listed as titanium nitride), GHS and regulatory sections",
      "id": "CID 93091",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/93091/JSON",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NCBI)"
    },
    "usgs-mcs2026-titanium": {
      "title": "Mineral Commodity Summaries 2026, Titanium and Titanium Dioxide",
      "id": "USGS MCS 2026, February 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "yu2014": {
      "title": "Phase stability, chemical bonding and mechanical properties of titanium nitrides: a first-principles study (Yu, Zeng, Oganov, Frapper, Zhang)",
      "id": "arXiv:1411.1485",
      "url": "https://arxiv.org/pdf/1411.1485",
      "year": 2014,
      "kind": "paper",
      "license": "arXiv preprint (author license as listed on arXiv)"
    },
    "arxiv-1707-00676": {
      "title": "Optical, elastic and thermodynamic properties of TiN: a first-principles study",
      "id": "arXiv:1707.00676",
      "url": "https://arxiv.org/pdf/1707.00676",
      "year": 2017,
      "kind": "paper",
      "license": "arXiv preprint (author license as listed on arXiv)"
    },
    "goel2025": {
      "title": "Thermoelectric and electronic transport properties of thermal and plasma-enhanced ALD grown titanium nitride thin films (Goel and Kauppinen et al.)",
      "id": "doi:10.1039/d5na00914f (Nanoscale Advances, 2025; PMC12687283)",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12687283/",
      "year": 2025,
      "kind": "paper",
      "license": "CC BY 3.0 (per the article page)"
    },
    "jaxa2008": {
      "title": "Evaluation of Solid Lubricative Coatings after Space Environment Exposure Test (JAXA, MPAC and SEED experiment, symposium proceedings)",
      "id": "Proc. International Symposium on SM/MPAC&SEED Experiment, Tsukuba, 10 to 11 March 2008, p. 133",
      "url": "https://jaxa.repo.nii.ac.jp/record/5231/files/64307015.pdf",
      "year": 2008,
      "kind": "paper",
      "license": "JAXA repository (cited, not reproduced)"
    },
    "avs2004": {
      "title": "Oxidation Behavior of Titanium Nitride Films (H.-Y. Chen et al.), AVS 51st International Symposium, paper SE-TuP5",
      "id": "AVS 51st International Symposium, 16 November 2004",
      "url": "https://www2.avs.org/symposium2004/Papers/Paper_SE-TuP5.html",
      "year": 2004,
      "kind": "web",
      "license": "conference abstract (cited)"
    },
    "wikipedia-tin": {
      "title": "Wikipedia, Titanium nitride (appearance and composition only)",
      "url": "https://en.wikipedia.org/wiki/Titanium_nitride",
      "kind": "web",
      "license": "CC BY-SA"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/titanium-nitride/"
}