Materials/Ceramics/Technical ceramics
Carbides, nitrides and borides
carbide-nitride-boride-ceramicsAbout carbides, nitrides and borides
Hard ceramic carbides, nitrides and borides (silicon carbide, boron carbide, silicon nitride, titanium nitride, zirconium diboride and more): hardness, melting point and stiffness with sources.
These compounds combine carbon, nitrogen or boron with a metal or silicon. They are very hard, stay strong at high temperature and are used for cutting tools, armour, bearings, coatings and ultra-high-temperature parts.
Many of them are sold as powders, coatings or sintered parts, so the form behind every value matters and is stated on each page.
At a glance
- Highest density: Tantalum carbide (TaC) reaches 15 g/cm³. Lowest: Hexagonal boron nitride (h-BN) starts at 2 g/cm³. (20 of 23 grades have a sourced value.)
- Highest melting point: Hafnium carbide (HfC) reaches 3,982 °C. Lowest: MAX phase ceramics starts at 1,390 °C. (16 of 23 grades have a sourced value.)
- Highest thermal conductivity: Hexagonal boron nitride (h-BN) reaches 600 W/(m·K). Lowest: Titanium nitride (TiN) starts at 7.01 W/(m·K). (14 of 23 grades have a sourced value.)
Ranges run across the conditions each source reports (temper, heat treatment, form), measured at room temperature where the source says so.
How they compare
The same measurements for every material in the collection. A range means the grade has values under several conditions; "at least" means the source gives a specified minimum. "no data" means no sourced value yet. For ranked tables, open a benchmark.
| Material | Density | Melting point | Thermal conductivity | Young's modulus | Flexural strength | Thermal expansion |
|---|---|---|---|---|---|---|
| Aluminium carbide (Al4C3)interfacial carbide in aluminium-carbon and aluminium-SiC composites; thermochemical reference compound | 2.36 g/cm³ | 2,100 °C | no data | no data | no data | no data |
| Aluminium nitride (AlN)electrically insulating heat-spreading ceramic | 3.25 to 3.3 g/cm³ | no data | 140 to 180 W/(m·K) | 276 to 330 GPa | 300 to 375 MPa | 4.5 ppm/K |
| Boron carbide (B4C)extremely hard ceramic for armor, wear parts and neutron shielding | 2.5 gm/cm3 | no data | 45 to 100 W/(m·K) | 440 GPa | 320 to 450 MPa | 4.5 to 4.9 ppm/K |
| Hexagonal boron nitride (h-BN)electrical insulator and thermal ceramic | 2 to 2.1 g/cm³ | no data | 30 to 600 W/(m·K) | 47 to 80 GPa | 39.7 to 94 MPa | 0.4 to 3.1 ppm/K |
| Chromium diboride (CrB2)hexagonal metal boride ceramic; related hard coating chromium carbide (Cr3C2) included | 5.15 to 6.68 g/cm³ | 1,850 to 1,980 °C | no data | no data | no data | 11.1 ppm/K |
| Chromium nitride (CrN)hard, silver-grey nitride coating for tools, sliding parts and piston rings | 5.9 g/cm³ | 1,500 °C | no data | 200 GPa | no data | no data |
| Hafnium carbide (HfC)very high melting point ultra-high-temperature ceramic (carbide), a candidate for hypersonic leading edges and high-temperature coatings | 12.2 g/cm³ | 3,887 to 3,982 °C | no data | no data | no data | 6.59 ppm/K |
| Lanthanum hexaboride (LaB6)low work function boride used as a thermionic (hot) electron emitter | 4.72 g/cm³ | 2,255 °C | 47 W/(m·K) | no data | 200 MPa | 6.2 ppm/K |
| MAX phase ceramicslayered machinable ceramic-metal hybrid for furnace heating elements, sliding parts and machinable high-temperature parts | 4.47 g/cm³ | 1,390 °C | 43 W/(m·K) | 265 GPa | no data | no data |
| Metal borides (TM borides)family of hard transition-metal borides: ZrB2, HfB2, NbB2, TaB2, WB, Co2B/CoB and the FeB/Fe2B boride layers on steel | 5.56 to 12.6 g/cm³ | 3,037 to 3,245 °C | 16 to 60 W/(m·K) | 248 to 489 GPa | no data | 5.9 to 8.2 ppm/K |
| Molybdenum carbide (Mo2C)hard refractory carbide for wear parts and tool materials, and a noble-metal-free electrocatalyst for hydrogen evolution | 9.18 to 9.2 g/cm³ | 2,687 to 2,690 °C | no data | no data | no data | no data |
| Molybdenum disilicide (MoSi2)high-temperature electric heating element material (dense silicide cermet, sold as Kanthal Super) | 5.6 to 6.5 g/cm³ | no data | 15 to 30 W/(m·K) | 407 GPa | 450 MPa | 7 to 8 ppm/K |
| Niobium carbide (NbC)hard refractory carbide for grain control in cemented carbide, wear coatings and carbide ceramics | 7.82 g/cm³ | 3,500 to 3,608 °C | no data | no data | no data | no data |
| Shapal (AlN-BN)machinable insulating ceramic that conducts heat | 2.88 to 2.95 g/cm³ | no data | 90 to 92 W/(m·K) | 176 to 186 GPa | 294 to 300 MPa | 4.8 to 5 x10-6/°C |
| Silicon carbide (SiC)structural ceramic and power semiconductor (4H polytype) | 3 to 3.17 g/cm³ | no data | 140 to 490 W/(m·K) | 370 to 421 GPa | 346 to 480 MPa | 4.4 ppm/K |
| Silicon nitride (Si3N4)structural ceramic | 2.53 to 3.37 g/cm³ | no data | 24 to 29 W/(m·K) | 180 to 320 GPa | 670 to 900 MPa | 1.4 to 3.2 ppm/K |
| Tantalum carbide (TaC)ultra-high-temperature ceramic (carbide), a candidate for hypersonic flight structures and a hard coating for hot tools | 13.9 to 15 g/cm³ | 3,880 °C | 22 W/(m·K) | no data | 96 to 291 MPa | 6.3 ppm/K |
| Titanium carbide (TiC)hard refractory carbide for cermet cutting tools, wear coatings and bearing surfaces | 4.93 g/cm³ | 3,017 to 3,160 °C | no data | 444 GPa | no data | no data |
| Titanium diboride (TiB2)hard, electrically conductive ultra-high-temperature ceramic (boride) | 4.5 g/cm³ | 3,225 °C | 60 to 120 W/(m·K) | 500 to 565 GPa | 400 to 1,000 MPa | 7.4 to 8.6 ppm/K |
| Titanium nitride (TiN)hard, golden-coloured ceramic coating and bulk ceramic (nitride) | no data | at least 2,900 °C | 7.01 to 27 W/(m·K) | 500 GPa | no data | no data |
| MSi2microelectronics contact silicides and oxidation-resistant silicide coatings (WSi2, TiSi2, TaSi2, CrSi2, NbSi2, FeSi2) | 4.13 to 9.3 g/cm³ | 1,490 to 2,200 °C | no data | no data | no data | no data |
| Zirconium carbide (ZrC)very high melting point ultra-high-temperature ceramic (carbide), a candidate for hypersonic leading edges and nuclear thermal propulsion coatings | 6.73 g/cm³ | 3,532 °C | 17.5 to 40 W/(m·K) | 435 to 464 GPa | 407 to 460 MPa | 4 to 10.2 ppm/K |
| Zirconium nitride (ZrN)hard, yellow nitride ceramic used as a protective and diffusion-barrier coating | 7,090 kg m-3 | 2,960 °C | no data | no data | no data | no data |
What these materials are made of
Composition by weight, as printed in the sources for each grade (the first constituents listed).
| Material | Main constituents |
|---|---|
| Chromium diboride (CrB2) | Cr 70.6% · B 29.4% |
| Molybdenum carbide (Mo2C) | Mo 94.1% · C 5.9% |
| Molybdenum disilicide (MoSi2) | Mo 63.1% · Si 36.9% |
| Niobium carbide (NbC) | Nb 88.6% · C 11.4% |
| Shapal (AlN-BN) | AlN 71 to 74% · BN 26% |
| Silicon nitride (Si3N4) | Si3N4 85 to 92% · RE2O3/Al2O3 sintering-aid blend 8 to 15% |
| MSi2 | Si 8.4% · W 27.5% · Ti 7.1% · Ta 27.0% · Cr 7.8% · Nb 13.9% · Fe 8.3% |
Where they are used
| Use | Grades |
|---|---|
| Substrates for electronic packages, IC packages and power transistor bases | Aluminium nitride (AlN) |
| Heat sinks | Aluminium nitride (AlN), Shapal (AlN-BN) |
| Semiconductor heater plates and chucks | Aluminium nitride (AlN) |
| B4C particles in an aluminium alloy 6061 metal matrix composite for neutron shielding | Boron carbide (B4C) |
| Hot-pressed B4C ballistic armor tiles | Boron carbide (B4C) |
| Wear-resistant nozzles, including grit-blast slurry nozzles | Boron carbide (B4C) |
| Insulators and components in space electric propulsion | Hexagonal boron nitride (h-BN) |
| High-voltage electrical insulator with high thermal conductivity | Hexagonal boron nitride (h-BN) |
| Microwave components and high-temperature electrical insulators | Hexagonal boron nitride (h-BN) |
| HVOF wear-resistant coatings on machinery and turbine blades | Chromium diboride (CrB2) |
| Erosion and corrosion protection coatings on cast iron components | Chromium diboride (CrB2) |
| Oxidation-protective thin film (laboratory only) | Chromium diboride (CrB2) |
| Piston rings for internal combustion engines (PVD coating on the sliding surface) | Chromium nitride (CrN) |
| Wear parts, machinery components and injection moulds | Chromium nitride (CrN) |
| Cutting and forming tools (metal forming) | Chromium nitride (CrN) |
| Carbon-carbon nozzle extension coating with embedded HfC and ZrB2 (NASA SBIR Phase 2, arc-jet test) | Hafnium carbide (HfC) |
When each grade fits
| Material | Best for | Weakest at |
|---|---|---|
| Aluminium carbide (Al4C3) | Thermochemical reference data for the carbide that forms at aluminium-carbon and aluminium-SiC interfaces, and for judging how much of it a composite can tolerate | Water and moist air: it releases flammable methane and heat (CAMEO, Wikipedia). Its melting point is not settled, since Wikipedia gives 2100 C as the melting point and 1400 C as the decomposition temperature |
| Aluminium nitride (AlN) | Electronic substrates, packages and heat spreaders where heat must leave a part without conducting electricity. | Water and humid storage: it hydrolyzes slowly, and the sources print no moisture limit. Thermal values also differ by grade. |
| Boron carbide (B4C) | Hard, wear-resistant parts such as blast nozzles and armor tiles, and neutron shielding where boron content matters (Saint-Gobain datasheet; NASA 2023 composite study) | Brittleness: flexural strength of 425 MPa and fracture toughness of 3.1 MPa x m1/2 (Saint-Gobain), and loss of quality and hardness in hot air with traces of nitrogen (Varadachari et al. 2018) |
| Hexagonal boron nitride (h-BN) | Electrical insulation and microwave or high-temperature insulating parts, where the 88 kV/mm dielectric strength and the 850 °C air limit of Grade A matter | Strength across or at high temperature: HP bending strength parallel to pressing falls from 39.7 MPa at 25 °C to 9.8 MPa at 600 °C, and oxidation in ambient air begins near 900 °C |
| Chromium diboride (CrB2) | Silicon-alloyed CrB2 films that must resist oxidation at 1100 to 1200 degC in air (laboratory films only; the paper gives an oxide scale of about 400 nm) | Few measured bulk properties (most CrB2 values here are calculated or from a powder safety data sheet) and conflicting hazard classifications for CrB2 between PubChem and the supplier |
| Chromium nitride (CrN) | Hard, wear-resistant PVD coatings on sliding parts, piston rings and cutting or forming tools, where service stays below about 700 °C in air | Oxidation in air from about 700 °C, and micro-cracking or peeling of the coating under load (patent background) |
| Hafnium carbide (HfC) | Very high melting point ceramic parts and coatings where a protective layer keeps air away from the surface, such as hypersonic leading edges and nozzle liners | Oxidation in air from 400 to 500 degC (Gaydaychuk et al. 2022), and low toughness, with no measured fracture toughness for HfC found in this run |
| Lanthanum hexaboride (LaB6) | Hot electron sources in electron beam instruments and Hall thruster hollow cathodes, where a low work function matters more than oxidation resistance in air | Oxidation in air from 500 degC, and oxygen poisoning of the emitter in oxygen-rich plasma |
| MAX phase ceramics | Electric heating elements that run hot in vacuum or inert gas, and machinable bulk parts (patent US6903313B2; Barsoum and El-Raghy 1997) | Oxidation in air above about 1100 to 1200 degC (patent), and decomposition into TiC above about 1400 degC in vacuum (Pang et al. 2009) |
| Metal borides (TM borides) | Hard, high-melting diboride parts and coatings where ZrB2 or TaB2 is needed, and boride layers that give steel a hard, wear-resistant surface (Fe2B) | Brittleness and few measured bulk values for most borides (only ZrB2, TaB2 and NbB2 have sourced bulk values here, and FeB fractures easily under load) |
| Molybdenum carbide (Mo2C) | Hard, high-melting carbide powder for wear parts and tool materials (vendor claims), and noble-metal-free hydrogen-evolution electrocatalysis in both acid and alkaline water (Hussain et al. 2019) | Hardness, thermal conductivity and expansion of pure Mo2C are not sourced in this file. The powder oxidises in steam or CO2 from about 600 °C, and it is a dust-forming powder that the SDS says to keep from dispersing |
| Molybdenum disilicide (MoSi2) | Electric heating elements in air furnaces for heat treatment, forging, sintering and glass melting, at element temperatures up to about 1700 to 1850 degC | Brittleness below about 1200 degC (Kanthal), and low-temperature oxidation near 500 degC that forms yellowish MoO3 powder |
| Niobium carbide (NbC) | Controlling grain growth in WC-10Co cemented carbide cutting and wear tools (Megret et al., 2025), and wear coatings reinforced with NbC particles (Gunen et al., 2024) | One supplier classes the powder as a flammable solid, and the oxidation of NbC in air is not sourced here. Hardness, elastic modulus and thermal conductivity of pure NbC are not sourced in this file, and the two melting points disagree. |
| Shapal (AlN-BN) | Machined ceramic parts that must conduct heat, insulate electrically and stay dimensionally stable: heat sinks, insulating plates and vacuum fixtures | Brittleness and spread between sheets: thermal conductivity is printed as 90 to 100 W/mK at room temperature and density as 2.88 to 2.95 g/cm3, and the sources give no Weibull modulus |
| Silicon carbide (SiC) | Hard, stiff ceramic parts and high-voltage semiconductor devices where a wide band gap and high breakdown field matter (Toshiba's 4H-SiC table versus silicon) | Brittleness as a ceramic: flexural strength of 346 MPa and fracture toughness near 2.8 MPa·m½ for sintered material, and a Weibull modulus of 11.0 (NIST) |
| Silicon nitride (Si3N4) | Structural parts and bearing elements where low mass, wear resistance, high temperature capability, or thermal shock resistance matter. | Grade-sensitive performance and brittle contact damage; select a process and grade, and use its own design data. |
| Tantalum carbide (TaC) | Very hard, very high melting point ceramic parts and coatings where a protective layer handles oxidation, such as coatings for steel moulds and a candidate for hypersonic structures | Oxidation in air from about 700 degC for coatings (CVD specification), and a flammable powder (H228 in the supplier SDS) |
| Titanium carbide (TiC) | Hard wear coatings and bearing surfaces (NASA records of 1980 and 1988), and cermet cutting tools with a carbide or carbonitride hard phase (Kennametal patent) | Oxidation in air above about 225 °C, and a flammable, dust-explosive powder (NextSDS H228; ICSC 1319). Hardness, thermal conductivity and thermal expansion of monolithic TiC are not sourced in this file |
| Titanium diboride (TiB2) | Hard, stiff, electrically conductive ceramic parts and wear surfaces, such as cathodes and cutting tools, where a melting point near 3225 degC matters more than oxidation resistance | Oxidation in air at high temperature (the review calls resistance inadequate, and B2O3 volatilises as the temperature rises, per Ozkan et al.) and brittleness (Weibull modulus of 11, NIST) |
| Titanium nitride (TiN) | 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 | 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) |
| MSi2 | Low-resistivity silicide contacts in microelectronics (TiSi2 C54, WSi2) and high-melting silicide coatings | Oxidation at intermediate temperatures for NbSi2 and CrSi2, and no flight or space data for any of the six compounds |
| Zirconium carbide (ZrC) | Hard, stiff, high melting point ceramic parts and coatings where oxidation is handled by a protective layer, such as hypersonic leading edges and nozzle liners | Oxidation in air above about 600 degC (the review) and brittleness, with little plastic deformation before fracture |
| Zirconium nitride (ZrN) | Hard protective coatings on steel for wear and corrosion tests, where a high melting point and a hard surface both matter | Oxidation in air. No readable source in this run gives an oxidation onset temperature for ZrN, so the limit in hot air is unverified |
Materials
carbide-nitride-boride-ceramics/al4c3
Carbides • 14 sourced entries • 5 sources • 2026
carbide-nitride-boride-ceramics/aln
Nitrides • 43 sourced entries • 8 sources • 2026
carbide-nitride-boride-ceramics/b4c
Carbides • 19 sourced entries • 9 sources • 2026
carbide-nitride-boride-ceramics/h-bn
Nitrides • 37 sourced entries • 8 sources • 2026
carbide-nitride-boride-ceramics/crb2
Ultra-high-temperature ceramics • 19 sourced entries • 12 sources • 2026
carbide-nitride-boride-ceramics/crn
Nitrides • 21 sourced entries • 8 sources • 2026
carbide-nitride-boride-ceramics/hfc
Carbides • 19 sourced entries • 10 sources • 2026
carbide-nitride-boride-ceramics/lab6
Ultra-high-temperature ceramics • 17 sourced entries • 10 sources • 2026
carbide-nitride-boride-ceramics/max
Carbides • 18 sourced entries • 12 sources • 2026
carbide-nitride-boride-ceramics/tm-borides
Ultra-high-temperature ceramics • 31 sourced entries • 19 sources • 2026
carbide-nitride-boride-ceramics/mo2c
Carbides • 14 sourced entries • 11 sources • 2026
carbide-nitride-boride-ceramics/mosi2
Ultra-high-temperature ceramics • 23 sourced entries • 12 sources • 2026
carbide-nitride-boride-ceramics/nbc
Carbides • 15 sourced entries • 13 sources • 2026
carbide-nitride-boride-ceramics/aln-bn
Nitrides • 32 sourced entries • 9 sources • 2026
carbide-nitride-boride-ceramics/sic
Carbides • 35 sourced entries • 11 sources • 2026
carbide-nitride-boride-ceramics/si3n4
Nitrides • 36 sourced entries • 9 sources • 2026
carbide-nitride-boride-ceramics/tac
Carbides • 13 sourced entries • 7 sources • 2026
carbide-nitride-boride-ceramics/tib2
Ultra-high-temperature ceramics • 30 sourced entries • 10 sources • 2026
carbide-nitride-boride-ceramics/tic
Carbides • 15 sourced entries • 14 sources • 2026
carbide-nitride-boride-ceramics/tin
Nitrides • 17 sourced entries • 8 sources • 2026
carbide-nitride-boride-ceramics/msi2
Ultra-high-temperature ceramics • 15 sourced entries • 29 sources • 2026
carbide-nitride-boride-ceramics/zrc
Carbides • 29 sourced entries • 8 sources • 2026
carbide-nitride-boride-ceramics/zrn
Nitrides • 15 sourced entries • 8 sources • 2026