Performance characteristics and differences between alumina ceramics and aluminum nitride ceramics

Release time：2024-09-11click：2

Aluminum Nitride Ceramic (Aluminum Nitride Ceramic) is a ceramic with aluminum nitride (AIN) as the main crystal phase.
AIN crystal is a covalently bonded compound with [AIN4] tetrahedron as the structural unit, with Wurtzite structure, which belongs to the hexagonal crystal system.
Chemical composition: AI 65.81%, N 34.19%, specific gravity 3.261g/cm3, white or off-white, colorless and transparent single crystal, sublimation decomposition temperature under normal pressure is 2450°C. It is a high-temperature heat-resistant material. Thermal expansion coefficient(4.0-6.0)X10-6/℃. The thermal conductivity of polycrystalline AIN reaches 260W/(m.k), which is 5-8 times higher than alumina, so it has good thermal shock resistance and can withstand extreme heat of 2200°C. In addition, aluminum nitride has the property of not being corroded by molten aluminum, other molten metals, and gallium arsenide. It has excellent corrosion resistance to molten aluminum in particular.
Performance Metrics
(1) The thermal conductivity is high (about 320W/m·K), close to BeO and SiC, and more than 5 times that of Al2O3;
(2)Thermal expansion coefficient (4.5×10-6℃) matches Si (3.5-4×10-6℃) and GaAs (6×10-6℃);
(3) Excellent various electrical properties (dielectric constant, dielectric loss, volume resistivity, dielectric strength);
(4) Good mechanical properties, higher flexural strength than Al2O3 and BeO ceramics, and can be sintered under normal pressure;
(5) Good optical transmission characteristics;
(6) Non-toxic.

Alumina ceramic is a very wear-resistant precision ceramic material that is widely used in various industries. Because of its superior performance, its application in modern society has become more and more extensive, meeting the needs of daily use and special performance.
The main molding methods of alumina ceramic products are: Dry pressing, isostatic pressing, injection molding and tape casting, Different product shapes, sizes, complex shapes and precision products require different molding methods. Alumina ceramic products sintered at high temperatures can only be processed using diamond grinding processes.
Alumina ceramic materials have extremely high hardness and wear resistance, strong corrosion resistance, high temperature resistance, corrosion resistance and biological inertness. In addition, alumina sintered at high temperatures can be highly polished and is widely used in many fields, such as ceramic sheets, ceramic rods, ceramic substrates, ceramic tubes, etc. The purity of common alumina ceramics is 90%-99.9%.
Performance Metrics
(1) High hardness. Rockwell hardness is HRA80-90, which is second only to diamond in hardness and far exceeds the wear resistance of wear-resistant steel and stainless steel.
(2) Excellent wear resistance. Measured by professional research institutions, its wear resistance is equivalent to 266 times that of manganese steel and 171.5 times that of high chromium cast iron. According to our customer follow-up surveys for more than ten years, under the same working conditions, it can extend the service life of the equipment by at least ten times. above.
(3) Light weight. Its density is 3.7~3.95g/cm³, which is only half that of steel, which can greatly reduce the equipment load.