Is there a relationship between thermal conductivity and density?

There is a certain relationship between thermal conductivity and density of thermal conductive silica gel sheet.

Thermal conductivity is a physical quantity that measures the thermal conductivity of a material. It represents the heat transferred through a unit area in a unit time at a unit temperature gradient. Density, however, is the ratio of material mass to volume, reflecting the compactness of the material.

With the increase of the density of the thermal conductive silica gel sheet, the internal voids are reduced, and the contact between the particles is closer, so that more heat conduction paths are formed. This filling effect helps to improve the thermal conductivity. The increase of density may change the scattering of phonons, reduce the energy loss, and further improve the thermal conductivity. However, too high density may also lead to changes in the internal structure of the material, such as the generation of new phase transitions or microscopic defects, which may instead reduce the thermal conductivity. Therefore, there is a very good density range to achieve a good thermal conductivity. It is found that the thermal conductivity of the silicone sheet is improved when the density of the sheet is increased within a certain range.

However, when the density exceeds a certain critical value, the growth rate of thermal conductivity will slow down or even decline.

In the selection of thermal conductivity silica gel sheet, in addition to considering the thermal conductivity and density, but also need to consider the mechanical strength, flexibility, weather resistance and other performance indicators of the material. At the same time, too high density may also increase material costs and production difficulties. Therefore, the appropriate density range should be selected according to the specific needs to achieve good heat dissipation effect.

In summary, there is a certain relationship between the thermal conductivity and the density of the thermal conductive silica gel sheet, but it is not a simple positive or negative correlation. In practice, it is necessary to consider a variety of factors to determine the good density and thermal conductivity range.