What are the advantages of Aluminum Nitride Ceramic Crucible?
Oct 18, 2023
Crucible made of refractory material is used to melt some things, such as steel, iron or even glass, aluminum and so on. The crucible is in various shapes, square, round and pot shape, which can be customized according to the drawings, and the size can be stereotyped at will, and the common crucible materials are high-purity alumina, corundum, graphite, zirconia, aluminum nitride and so on.
1.Why choose aluminum nitride ceramic crucible?
Aluminum nitride in ceramics at room temperature and high temperature have good corrosion resistance, stability, in 2450 ℃ before decomposition, can be used as high temperature refractory materials, such as crucibles, casting molds. Aluminum nitride ceramics cannot be copper, aluminum, silver and other substances wetting as well as resistance to aluminum, iron, aluminum alloy dissolution, can be a good container and high-temperature protective layer, such as thermocouple protection tubes and sintering appliances; can also resist high-temperature corrosive gases, such as used in the preparation of aluminum nitride ceramics electrostatic chuck this important semiconductor manufacturing equipment, high-end parts. Due to aluminum nitride on gallium arsenide and other molten salts performance stability, aluminum nitride crucible instead of glass to synthesize gallium arsenide semiconductor, can eliminate the pollution from the silicon in the glass, to obtain high purity gallium arsenide semiconductor.
2. Characteristics of aluminum nitride ceramic crucible
1)High thermal conductivity (about 230W/m-K), close to BeO and SiC, more than 5 times of Al2O3.
(2) Thermal expansion coefficient (4.5×10-6°C) matches Si (3.5~4×10-6°C) and GaAs (6×10-6°C).
(3) Excellent various electrical properties (dielectric constant, dielectric loss, body resistivity, dielectric strength);
(4) Good mechanical properties, higher flexural strength than Al2O3 and BeO ceramics, and can be sintered at atmospheric pressure.
(5) High purity and non-toxic.
Aluminum nitride is an important structural ceramic material. It is a super-hard substance, resistant to wear and oxidation at high temperatures. Its hardness is second only to diamond, boron carbide and cubic boron nitride, and aluminum nitride ceramics rank fourth in inorganic materials. At present, the high-density aluminum nitride obtained by hot pressing and sintering method has high strength and good antioxidant property, and it can be kept without deformation under high temperature, so it has excellent performance in the crucible material.
3. How is the aluminum nitride ceramic crucible made?
The preparation process of aluminum nitride ceramic crucible: powder synthesis, molding, sintering.
Powder synthesis: Aluminum nitride powder is used as the raw material for the preparation of final ceramic products, and its purity, particle size, oxygen content and the content of other impurities have an important influence on the thermal conductivity of the subsequent finished products, subsequent sintering and forming process, and each production step will decide whether the performance of the product is excellent or not. Aluminum nitride powders are synthesized by the following methods: direct nitriding, carbothermal reduction, self-propagating high-temperature synthesis, and chemical vapor deposition.
Forming: Dry pressure or isostatic pressure
Sintering: Aluminum nitride crucibles can be subjected to temperatures of about 1300°C in air without overall oxidation, although the process begins after 700°C. The process can take place at temperatures of up to 700°C in a vacuum. In a vacuum, alumina ceramics decompose at 1800°C and melt at 2200°C, protected by an inert atmosphere. In general, alumina ceramic products operate at temperatures of 800°C in air, 1700°C in vacuum and 2100°C in an inert atmosphere.
CNC Finishing: To process aluminum nitride ceramics with 2200° sintering temperature, you need to use ceramic CNC for finishing, ceramic CNC can process aluminum nitride ceramic crucible with high precision. Because the hardness of aluminum nitride ceramics is very high, advanced equipment and professional processing technology will determine the precision of aluminum nitride ceramic crucible.
As a material that can withstand high temperature for a long time and has super high resistance to thermal vibration, aluminum nitride ceramic is undoubtedly the best choice for crucible material. Xiang Ceramics has many years of experience in advanced ceramics production and manufacturing, equipped with high-end production facilities, and possesses the advanced technology level that leads the domestic counterparts. We are also the first-class supplier of various famous enterprises around the world. We support product customization and welcome your inquiry via below ways:
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