What should be paid attention to when using alumina ceramic crucibles from crucible manufacturers?

Porcelain crucible manufacturer Crucible production materials can be divided into three categories: crystalline natural graphite, plastic refractory clay, and calcined hard kaolin clay skeleton clinker. For example, silicon carbide, alumina, silicon carbide, and ferrosilicon are used as the framework clinker of crucibles. This clinker plays an important role in improving the product quality, density, and mechanical strength of crucibles.

Porcelain crucible manufacturer Alumina ceramic crucibles use α-alumina as a raw material, and their alumina content is generally above 99%. The higher the alumina content in the material, the higher the sintering temperature, and the better the high-temperature resistance. It has strong corrosion resistance and excellent chemical stability for acidic and alkaline solutions. Compared with stainless steel crucibles, problems such as burn-through and deformation will not occur.

So when using Porcelain crucible manufacturer alumina ceramic crucibles, the following precautions should be noted:

1. The melting point is 1773.5℃, the operating temperature should not exceed 1200℃, and it should not be directly heated by open flame.

2. Do not use excessive force to avoid deformation or unevenness. Do not use the tip of a glass rod to put materials into the crucible.

3. Do not use this product to heat or dissolve substances of unknown composition.

4. Do not heat or melt alkali metal oxides, hydroxides, barium oxide, sodium thiosulfate, substances containing phosphorus and a large amount of sulfur; nitrates, oxides, and chlorides of alkali metals will form brittle platinum phosphide and platinum sulfide at high temperatures, which will cause corrosion.

5. High-temperature heating should not contact any other metals (iron plates, electric furnaces, etc.). When placing it in a high-temperature furnace, be careful not to touch the electric corner.

6. Do not burn or heat samples and compounds containing heavy metals such as lead, bismuth, tin, arsenic, silver, mercury, and copper.

7. Halogens such as aqua regia, bromine water, hydrochloric acid, and oxidants (chlorates, nitrates, permanganates, manganese dioxide, chromates) should not be processed. Ferric chloride has a significant corrosive effect on them, so it cannot be contacted with ferric chloride.

8. It must be kept clean, and the inside and outside must be bright. After long-term burning, its appearance may darken. Over time, it will penetrate deep inside, leading to fragile fractures. Therefore, it is necessary to remove unclean things.

Crucibles in the refractory materials industry are usually used to melt certain things, such as molten steel, molten iron, and even glass, aluminum liquid, etc. Crucibles come in various shapes, including square, round, and basin shapes. They can be customized according to drawings and samples, and the size can be arbitrarily shaped. Generally speaking, commonly used crucible materials include high alumina, corundum, graphite, zirconia, aluminum nitride, etc.

Porcelain crucible manufacturer The advantages of aluminum nitride ceramic crucibles are as follows:

(1) High thermal conductivity (approximately 320 W/m·K), close to BeO and SiC, more than 5 times that of Al2O3;

(2) Thermal expansion coefficient (4.5) × 10-6℃, silicon (3.5~4 × 10-6℃), gallium arsenide (6 × 10-6℃); matching;

(3) Various electrical properties (dielectric constant, dielectric loss, volume resistivity, dielectric strength) are all excellent;

(4) Good mechanical properties, flexural strength higher than Al2O3 and BeO ceramics, can be sintered at normal pressure;

(5) High purity;

(6) Good light transmission characteristics;

(7) Non-toxic;

(8) It can be made by the casting process.