Boron carbide hardness
Boron carbide (B ₄ C), also known as black diamond, is an inorganic substance with a relatively high hardness. The following is a detailed explanation of the hardness of boron carbide:
1、 Mohs hardness
The Mohs hardness of boron carbide is usually between 9.3 and 9.5, making it one of the three hardest materials known, second only to diamond (with a Mohs hardness of 10) and cubic boron nitride.
2、 Microhardness
The microhardness of boron carbide is also very high, and its microhardness value varies depending on different testing conditions and preparation processes. The microhardness is generally between 3500kgf/mm ² and 6700kg/mm ². Some sources indicate that its microhardness ranges from 3000 kg/mm ² to 5500~6700 kg/mm ².
3、 Other physical properties
In addition to high hardness, boron carbide also has the following physical properties:
Density: The density of boron carbide is about 2.46g/cm ³ to 2.52g/cm ³, which is relatively low, only about one-third of that of steel.
Melting point: Boron carbide has a melting point of approximately 2447 ℃ to 2450 ℃ and is a high melting point material.
Elastic modulus: The elastic modulus of boron carbide is as high as 450GPa, indicating its good resistance to deformation.
The thermal expansion coefficient of boron carbide is relatively low。
Thermal conductivity: Boron carbide has a high thermal conductivity, which is beneficial for heat transfer and dissipation.
4、 The relationship between hardness and material properties
The hardness of boron carbide is closely related to its material properties. For example, the microhardness of boron carbide products increases with the increase of temperature, because as the temperature rises, the migration speed of pores in the sintered body accelerates, the densification process of boron carbide products intensifies, the bulk density of the material increases, and the microhardness increases. In addition, the hardness of boron carbide is also related to factors such as its preparation process and grain size.
boron carbide with high hardness, widely used in tank armor, bulletproof vests, and many industrial applications.