# How Thermal Conductivity Materials Are Calculated

Jan 12

In the aerospace industry, thermal conductivity is an important material property that determines how quickly heat can be transferred through a component. This is because fast transfer of heat is a key factor in maximizing the efficiency and performance of an engine or other aircraft component. In addition, it is important to understand how thermal conductivity is calculated and the factors that influence its value.

The physics of heat flow through a solid is explained by the Second Law of Thermodynamics, which states that a temperature gradient will cause energy to move across the surface of a material from a higher to a lower temperature. The thermal conductivity of a material, measured in Wm-1K-1, is the rate at which heat travels through the material due to this gradient. The thermal conductivity of a material can be determined experimentally or estimated using an equation based on the density, thickness, and temperature of the material.

While there are many factors that can impact Understanding Thermal Conductivity Materials, one of the most significant is its thickness. Essentially, thicker materials have higher thermal conductivity than thinner ones because they are more dense and have closer packing of atoms and molecules, resulting in greater heat transfer through the material. In addition to thickness, the thermal conductivity of a material can be influenced by the type and amount of impurities present in the material. For example, pure metals have high thermal conductivity, while alloys have low thermal conductivity due to the fact that they are not pure.

Another factor that can affect the thermal conductivity of a material is its phase. For example, liquids and vapors have much higher thermal conductivity than solids because they can more easily pass heat between adjacent molecules. Similarly, certain changes in pressure can also affect the thermal conductivity of a material, with higher pressure typically producing higher values than lower pressures. This is because higher pressures create a tighter packing of atoms and molecules, which can increase the thermal conductivity of a material.

In addition to these factors, the thermal conductivity of a material is influenced by its shape and composition. For instance, a thin film material will have a different thermal conductivity than a bulk material because it has an extremely high surface area that is exposed to the air. In addition, some materials exhibit anisotropy in their thermal conductivity, with the conductive properties being different along each of its axes. This is often the case in layered materials such as amorphous silicon and copper, where a higher conductivity is seen in the x-axis than in the y-axis.

Whether a material has high or low thermal conductivity is important depending on the application and environmental conditions. For example, a high-quality metal such as stainless steel has a very high thermal conductivity, while aerogel or insulation used in homes has a very low thermal conductivity. In order to design the most effective components for a given application, it is necessary to consider the material’s thermal conductivity as well as other physical properties such as specific heat and electrical conductivity. For more information on how to calculate and measure the thermal conductivity of your materials, contact a Xometry representative today.