Industry News

- March 11, 2021

Influence of thermal conductivity

Graphite is the only non-metallic material whose thermal conductivity is greater than that of many metals such as aluminum and iron. The thermal conductivity of carbon materials has a considerable range of fluctuations, which depends on the raw material, production conditions, density, size, crystal orientation, and so on. The properties of non-graphitized materials, such as blanks to be graphitized, are significantly different from those after graphitization.

Due to the anisotropy of graphite, the heat flow mainly flows along the graphite plane. This orientation also exists in molded carbon products. This is particularly evident on extruded electrodes. The axial thermal conductivity of the electrode is much higher than the radial direction. The thermal conductivity of graphitized materials at room temperature is 126-211W/(m.℃); the thermal conductivity of non-graphitized materials is very low, fluctuating in the range of 4.22-8.45W/(m.℃). For mixtures containing carbon black, the thermal conductivity decreases significantly with the increase of carbon black content. If the thermal conductivity of the calcined product with petroleum coke as the main raw material is about 4.22W/(m.℃), the thermal conductivity of the mixed material containing 80% petroleum coke and 20% carbon black will be almost doubled.

The thermal conductivity of graphite materials decreases with increasing temperature. On the contrary, the non-graphitized carbon material blanks, on the contrary, with the increase of temperature, the thermal conductivity almost doubles under the temperature condition of 1000-1200℃, and it has become close to graphite materials at 2300℃. The thermal conductivity.