Tin Oxide Ceramic Parts

Tin oxide ceramic parts are ceramics with tin oxide as the main component.

The flexural strength is 80MPa. Linear expansion coefficient (4.5～5)×10-6/℃. It has excellent corrosion resistance to glass molten salt and non-ferrous metal melt at high temperature, good resistance to temperature sudden change and good electrical conductivity. After the tin oxide raw material is processed by batching and general ceramic technology, the green body is sintered in an oxidizing atmosphere at 1500-1550 °C. Used as glass electrofusion electrode, crucible for melting glass, etc.

Zhongwei Precision is committed to providing domestic and foreign customers with advanced ceramics with high strength, high toughness, wear resistance, corrosion resistance and high temperature resistance. It is a high-tech enterprise integrating R&D, production and sales of industrial precision advanced ceramic products in the field of precision ceramics. With a variety of modern high-precision equipment, it has independently realized the completion of the entire production process of ceramic parts from ceramic powder preparation, green body molding, high temperature sintering to ceramic material finishing.

Product Description

1. Implementation standards: the company strictly implements ISO9001 certification, and the products have passed ROHS, FDA EU certification, etc.

2. Product material standards: ISO, GB, ASTM, SAE, EN, DIN, BS, AMS, JIS, ASME, DMS, TOCT, GB

3. Main processes: grouting, injection molding, tape casting, isostatic pressing, 3D printing

4. Available materials for ceramics:

It mainly produces finished ceramic rods, ceramic tubes, ceramic rings, ceramic plates, ceramic suction cups, ceramic blades and other special-shaped ceramic structures. The main ceramic materials are alumina, zirconia, silicon carbide, silicon nitride, and aluminum nitride ceramics. High temperature resistance, wear resistance, corrosion resistance, acid and alkali resistance, anti-magnetic, pressure resistance. And 3D printing, etc. are customized according to customer requirements.

Combined tube, its high wear resistance effectively resists material wear and impact.

Product Performance

1. Tin oxide ceramics

Tin dioxide is an n-type semiconductor with finely dispersed white powder. It is an excellent transparent conductive material. Both have broad application prospects and are also the first commercial transparent conductive materials. In order to improve their conductivity and stability in industry, they are often doped. For example, doping with elements such as Sb, V and Ni can make the conductivity drastically increased. The ceramic material based on tin dioxide not only has good electrical conductivity and high density, but also has high temperature resistance, high temperature re-softening point and excellent corrosion resistance, so Tin oxide ceramic parts can be used as electrode materials for high temperature heating such as crucibles , thermocouple protective sleeve and chemical equipment lining, etc.

2. Properties of SnO2 ceramics

The thermal expansion coefficient of SnO2 ceramics is small (1/2 of that of alumina ceramics), the thermal conductivity is high, and the thermal stability is higher than that of alumina ceramics and zirconia ceramics. The volatilization rate of SnO2 ceramics is low at 1400 °C, and the volatilization is strong above 1500 °C. Therefore, SnO2 ceramics can only be used in an oxygen atmosphere below 1500 °C.

The specific resistance of pure SnO2 ceramics at room temperature is 1010~1011Ω·cm. However, adding divalent or trivalent metal oxides will reduce its specific resistance. For example, after adding Sb2O3 and CuO, the specific resistance of SnO2 is reduced by 7 to 8 orders of magnitude.

SnO2 ceramics have strong resistance to the erosion of glass liquid. At 1200 ℃, the corrosion resistance of SnO2 ceramic electrode to calcium glass is 1~2 times higher than that of fused corundum. At 1500 ℃, the alkali corrosion resistance is 4 times higher than that of fused corundum. It is also resistant to corrosion by lead glass, arsenic glass, iron glass, copper glass.

3. Preparation of SnO2 ceramics

Tin oxide ceramics are usually made of SnO2, and the SnO2 content is about 96% to 98%, see Table 1. When preparing the blanks, some additives must be added. According to the different requirements for product performance, additives are divided into two categories. One is the additives that promote sintering. Such additives include metal oxides such as gold, silver, copper, iron, nickel, and zinc. The other is an additive to reduce resistance, mainly oxides of arsenic, antimony, copper, uranium, strontium, niobium, etc. The amount added is determined by the performance requirements of the product, generally 0.5% to 2% (mass).

Table 1. Additive composition of Tin oxide ceramic parts

The refractory temperature is not lower than 1900℃, and it consists of equiaxed tin dioxide particles with standard optical constant size of 3~8μm. Forming generally adopts dry pressing or grouting. Tin oxide ceramics are usually fired in an oxidizing atmosphere at a temperature of 1450~1500°C. The surrounding medium atmosphere has an influence on the electrical conductivity of SnO2 ceramics. When the oxygen partial pressure is high, the oxygen molecules will enter the lattice of the solid phase to generate p-type electron conduction; when the oxygen partial pressure is low, such as in a reducing atmosphere, the crystal lattice is deficient in oxygen, and n-type electrons are generated Conductive. In general, SnO2 is mainly ionically conductive.

In order to improve the electrical conductivity of SnO2 ceramics at room temperature and the stability of electrical conductivity at different temperatures, the process of gas phase treatment and heat treatment can be used. Gas phase treatment is to use the volatilized vapor of tin halide (such as SnCl2, SnCl4, SnBrCl3, etc.) and the mixed gas containing free oxygen to deposit deeply on the surface of the product to produce dense compounds with high conductivity (such as SnO) or cermets in the pores. . The heat treatment is to heat the tin oxide ceramics to 1200 ° C and pass in inert gas (such as nitrogen, argon, etc.) to reduce the resistivity at room temperature by 6 to 7 orders of magnitude. The modification effect of vacuum is better than that of inert gas.

4. Use of SnO2 ceramics

Due to the small thermal expansion coefficient, large thermal conductivity and good high temperature thermal stability of SnO2 ceramics, it can be used as a high temperature thermal conductive material. Due to its high electrical conductivity at high temperatures, it can be used as a high-temperature conductive material. And because of its strong alkali resistance, it can be used as electrodes for special crucibles and glass capacitors.

Process After Sintering

Processing equipment: equipped with CNC engraving machine, centerless grinding, internal and external cylindrical grinding, surface grinding, CNC lathe machining center, wire cutting, turning, milling, grinding and other high-precision production and testing equipment.

Moulds and Inspection Fixtures

1. Mold service life: usually semi-permanent. (except for lost foam).

2. Mold delivery time: 10-25 days, (according to product structure and product size).

3. Tooling and mold maintenance: Zhongwei is responsible for precision parts.

Quality Control

1. Quality control: the defective rate is less than 0.1%.

2. Samples and trial run will be 100% inspected during production and before shipment, sample inspection for mass production according to ISDO standards or customer requirements.

3. Test equipment: roundness measuring instrument, three-coordinate measuring instrument, image coordinate measuring instrument, Hexagon three-coordinate measuring instrument, image measuring instrument, density measuring instrument, smoothness measuring instrument, micro Vickers hardness tester.