B4C
Boron carbide · Black diamond
Boron carbide is an exceptionally hard, stable ceramic compound used primarily for its durability in protective and abrasive applications.
About Boron carbide
Boron carbide is a robust, thermodynamically stable ceramic material composed of boron and carbon. As a wide-band-gap insulator, it exhibits exceptional structural integrity and chemical resistance, making it a cornerstone of modern materials science for demanding environments.
Its unique combination of low density and extreme hardness ensures its place as a critical component in ballistic protection and heavy-duty industrial applications. Its stability on the convex hull confirms its reliability as a structural material that maintains performance under significant mechanical stress.
Key Properties
Cross-validated computational properties for Boron carbide, aggregated across 3 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Reported Structures
Lowest-energy structures reported for B4C, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| Cm (No. 8) | monoclinic | 3.04 | 0.0000 | -7.997 | 2.54 |
| R-3m (No. 166) | trigonal | 1.51 | 0.0812 | -7.916 | 2.49 |
| P1 (No. 1) | triclinic | 0.00 | 0.0973 | -7.900 | 2.43 |
| R-3m (No. 166) | trigonal | 0.00 | 0.9018 | -7.095 | 1.99 |
| R-3m (No. 166) | trigonal | 0.00 | 1.0526 | -6.944 | 1.24 |
| P1 (No. 1) | triclinic | 0.00 | 1.3735 | -6.624 | 2.43 |
| Pm (No. 6) | Monoclinic | — | — | — | 2.79 |
| P1 (No. 1) | Triclinic | — | — | — | 3.42 |
| Cm (No. 8) | Monoclinic | — | — | — | 2.41 |
| P1 (No. 1) | Triclinic | — | — | — | 2.46 |
| Cm (No. 8) | Monoclinic | — | — | — | 2.61 |
| Cmmm (No. 65) | Orthorhombic | — | — | — | 2.44 |
Applications
Where Boron carbide is used.
Frequently Asked Questions
Common questions about Boron carbide, answered from cross-validated data.
What is B4C?
Boron carbide is an exceptionally hard, stable ceramic compound used primarily for its durability in protective and abrasive applications.
What is B4C used for?
What is the band gap of B4C?
Is B4C a metal, semiconductor, or insulator?
Is B4C thermodynamically stable?
What is the crystal structure of B4C?
What is the density of B4C?
How many polymorphs of B4C are known?
What elements does B4C contain?
Where does the data for B4C come from?
How It Compares
Within the carbide hard materials class.
Within the class of carbide hard materials, boron carbide is distinguished by its superior hardness and lightweight profile compared to metallic carbides like ZrC or HfC. While silicon-based carbides such as SiC are widely utilized for their thermal conductivity and semiconductor properties, boron carbide remains the preferred choice for applications where maximum hardness and impact resistance are the primary engineering requirements.
Related Compounds
Other Carbide Hard Materials in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
Analyze B4C in the Lattice Graph platform
Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.
Explore the Platform →