What is the thermal conductivity of the ceramic material

The thermal conductivity of different ceramic materials varies, usually between 1-10 W/(m·K).

Thermal conductivity refers to the heat conduction capacity of a substance, which refers to the ratio of the heat conduction per unit time to the product of the difference between the unit area and the unit temperature. The thermal conductivity of ceramic materials is closely related to internal structure, chemical composition, crystal structure, grain size, porosity, temperature and other factors. Under normal circumstances, the thermal conductivity of ceramic materials gradually decreases with the increase of grain size in the material. With the increase of temperature, the thermal conductivity generally changes to a small degree.

The thermal conductivity of common ceramic materials

1. Alumina ceramics

Alumina ceramics is an important high-temperature structural material. At room temperature, its thermal conductivity is usually 30-35 W/(m·K) and decreases slightly with increasing temperature. In addition, alumina ceramics have good insulation and mechanical properties, and also have excellent corrosion resistance in high temperature environments.

2. Zirconia ceramics

Zirconia ceramics have excellent mechanical properties, thermal properties and chemical stability, and have high application value. Its thermal conductivity is generally about 2-3 W/(m·K).

3. Silicon boronitride ceramics

Silicon boronitride ceramic is a new kind of ceramic material with high hardness, high strength and high corrosion resistance. Its thermal conductivity is about 20 W/(m·K), which is nearly 10 times higher than zirconia ceramics, and is an ideal high temperature thermal industrial material.

In addition to the above several ceramic materials, the thermal conductivity of other common ceramic materials (such as yttrium oxide ceramics, silicon carbide ceramics, etc.) is also different, but usually between 1-10 W/(m·K).

Understand the standard of ceramic thermal conductivity and master the thermal conductivity of ceramic materials

Concepts and standards for thermal conductivity of ceramics

Ceramic material is an important industrial material, and its thermal conductivity is one of the important indexes of its performance. Thermal conductivity is usually expressed in terms of thermal conductivity and is expressed in W/(m·K). The thermal conductivity of ceramic materials depends on the structure, composition, density, temperature and other factors. In general, the thermal conductivity of ceramic materials is low, usually between 1-10 W/(m·K).

At present, the international measurement methods for ceramic thermal conductivity mainly include ASTM C408, ISO 8894-1, EN 12667 and other standards. Among them, ASTM C408 standard is one of the United States ceramic standard test methods, mainly used to measure the thermal conductivity of high temperature ceramics. ISO 8894-1 and EN 12667 are European standards for measuring the thermal conductivity of ceramics and rocks.

Factors affecting thermal conductivity of ceramic materials

The size of the thermal conductivity of ceramic materials is not only affected by the characteristics of the material itself, but also affected by other factors, such as temperature, structure and so on.

1. Material composition and structure

The thermal conductivity of ceramic materials is closely related to its composition and structure. Common ceramic materials are mainly alumina ceramics, silicon nitride ceramics, zirconia ceramics and so on. The thermal conductivity of different ceramic materials is very different, for example, the thermal conductivity of silicon nitride is high, and the thermal conductivity of alumina is low.

2. Temperature

Temperature is one of the important factors affecting the thermal conductivity of ceramics. When the temperature is higher, the thermal conductivity of ceramic materials tends to increase.

3. Structure

The structure of ceramic material also has a certain influence on the thermal conductivity. For example, the lattice structure and crystal defects of ceramic materials can affect the thermal conductivity of the material.