Difference Between Boron Carbide and Boron Nitride
Nowadays, many people can’t tell the difference between boron nitride and boron carbide. The most important reason for this phenomenon is that the pronunciation is similar, but the two are actually different in performance.
1. Boron carbide is a hard black shiny crystal. The hardness is lower than that of industrial diamond, but higher than that of silicon carbide. Compared with most pottery, the brittleness is lower. It has a large thermal energy neutron capture section. Corrosion by heated hydrogen fluoride and nitric acid. Soluble in molten alkali, insoluble in water and acid. Relative density (d204) 2.508～2.512. Melting point 2350℃. Boiling point 3500℃.
2. Boron nitride is corrosion-resistant, has good electrical insulation, and has a specific resistance greater than 10-6Ω. cm; compressive strength is 170MPa; the thermal expansion coefficient in the c-axis direction is 41×10-6/°C and in the d-axis direction is -2.3×10-6; the maximum operating temperature in an oxidizing atmosphere is 900°C, However, it can reach 2800 °C in an inactive reducing atmosphere, and the lubricating performance is better at room temperature.