Thermal Conductivity of Materials to Conduct Heat
The term thermal conductivity describes how easily a material transmits heat energy. It is a physical property of materials that can vary depending on the type, structure, and state of the material. The inverse of thermal conductivity is thermal resistance, which measures how well a material resists the transfer of heat.
Understanding Thermal Conductivity Materials to conduct heat is determined by the types of atoms, molecules, or ions that comprise it. Metals tend to be good conductors because electrons in their atomic bonds can move freely throughout the material, allowing them to transfer heat quickly and efficiently. Non-metallic materials such as polymers and ceramics, on the other hand, have lower thermal conductivities because their atomic or molecular structures are rigid and less mobile.
A material’s thermal conductivity is also influenced by its thickness, which affects the way that heat travels within it. The simplest method to measure thermal conductivity is through steady-state techniques, where the temperature of the material is held constant over time. The resulting thermal conductivity is calculated as the rate of heat flow divided by the material’s thickness, and it is measured in units of Watts per meter Kelvin.
Another important factor that can influence a material’s thermal conductivity is its crystal structure, since the arrangement of its atoms will affect how easy it is for electrons to move through the lattice. Metals with a face-centered cubic structure, like copper and silver, tend to have higher thermal conductivities than metals with a body-centered cubic structure, such as iron.
Lastly, the way that a material’s atoms or molecules vibrate can also affect its thermal conductivity. For example, vibrations that are created by phonons can reduce the lattice thermal conductivity of a material. In order to reduce this effect, it is necessary to introduce scattering mechanisms that can disperse phonons, such as those found in alloys and nanocomposites.
In addition to these factors, the thermal conductivity of a material can be affected by its chemical composition. This is because impurities in a metal can cause its conductivity to decrease.
The thermal conductivity of a material is an important parameter to consider when selecting the material for an aerospace application. In general, a material with a high thermal conductivity is a good choice for electronic components that need to be cooled down quickly, such as processors or GPUs. In contrast, an insulating material such as aerogel or the insulation used in homes has a low thermal conductivity and is effective at preventing heat from passing through it.
The thermal conductivity of a material is highly dependent on its temperature gradient, and the characteristics of the materials that it contacts along this path. This is why good conductors of electricity (metals) are also good conductors of thermal energy, whereas insulators (such as wood and plastics) are poor conductors of electricity.