What is the Difference Between Boron Nitride and Graphite?

Boron nitride and graphite are both crystalline materials with different atomic compositions, resulting in distinct chemical and physical properties. The main differences between boron nitride and graphite include:

1. Elemental Composition: Boron nitride is composed of boron atoms, while graphite is composed of carbon atoms.
2. Chemical Properties: Boron nitride is an excellent thermal and chemical resistant refractory material, while graphite has excellent electrical conductivity.
3. Crystal Structure: Both boron nitride and graphite have a hexagonal lattice structure. However, graphite has non-polar homo-nuclear C-C intra-layer bonds, while boron nitride presents highly polar B-N bonds, resulting in different optimal stacking modes of the two materials in bulk form.
4. Interlayer Distance: Graphite and hexagonal boron nitride (h-BN) possess the same interlayer distance, despite their differences in interlayer bonding and atomic properties.
5. Mechanical Properties: Graphite has a compressive strength of 90 MPa, while hexagonal boron nitride has a range of 21 to 250 MPa. The density of graphite is 1.8 g/cm³, while hexagonal boron nitride ranges from 1.9 to 2.1 g/cm³.
6. Temperature Resistance: The maximum temperature for corrosion in graphite is 180°C, while hexagonal boron nitride can withstand up to 1140 to 2800°C. The maximum temperature for mechanical stability in graphite is 220°C, while hexagonal boron nitride can withstand up to 1030 to 2350°C.

In summary, boron nitride and graphite have different atomic compositions, leading to variations in their chemical and physical properties. They both possess a hexagonal lattice structure, but their interlayer bonding and atomic properties result in distinct mechanical and temperature resistance characteristics.

Comparative Table: Boron Nitride vs Graphite

Here is a table comparing the differences between boron nitride and graphite:

Boron nitride and graphite are both non-oxide engineering ceramics with hexagonal lattice structures. However, they differ in their atomic compositions, with boron nitride composed of boron and nitrogen atoms, and graphite composed of carbon atoms. This difference in composition results in various differences in their physical and chemical properties, as seen in the table above.