Aluminum Nitride Properties And Applications
Aluminum nitride has good oxidation resistance, chemical resistance, thermal shock resistance, mechanical strength, low dielectric constant, thermal expansion coefficient similar to that of silicon crystal, and high thermal conductivity. So it is widely used in machinery and other application fields. Below are the detailed properties: Thermal property The theoretical thermal conductivity of AlN is 320W/m•K, the thermal conductivity of the prepared polycrystalline AlN is generally 100~260W/m•K, and the room temperature thermal conductivity is 10~15 times that of Al2O3, which is close to BeO ( The theoretical thermal conductivity is 350W/m K), and when the temperature is higher than 200℃, the thermal conductivity is better than that of beryllium oxide; in the range of 25~400℃, the thermal expansion coefficient of pure AIN is 4.4×10-6K- 1, similar to the thermal expansion coefficient of silicon (3.4×10-6K-1). Electrical properties The room temperature cathode rate of pure AIN is greater than 1014Ω•cm, which is a good insulating material; the dielectric constant is about 8.0 (1MHz), which is equivalent to Al2O3; the dielectric loss is 10-4 (1MHz), and the dielectric withstand voltage is 14KV •mm-1, high electromechanical coupling coefficient (0.8%), piezoelectricity and negative yield. Mechanical properties At room temperature, the Vickers hardness of dense AIN ceramics...