Thermal Conductivity Materials for Aerospace conductivity
Aerospace materials need to have high thermal conductivity for the effective heat management in aircraft components to operate at lower temperatures. The development of new structural materials and renewed interest in existing materials is creating a greater demand for accurate thermal and electrical property data on these materials. This is especially critical for the selection of construction materials and prediction of operating characteristics at low temperature.
Thermal conductivity is a physical property of a material that describes how rapidly thermal energy (electromonism) can travel through the material from warmer areas to colder ones. The inverse of thermal conductivity is thermal resistivity, which measures the resistance of a material to thermal energy. The higher the thermal conductivity, the more rapid the transport of heat through a material.
Understanding Thermal Conductivity Materials thermal conductivity is defined as the constant of proportionality (k) dividing the rate of thermal energy (electromonism) transfer by the temperature gradient at which it occurs. In other words, k is the rate at which a unit area of the material transfers thermal energy per second. The thermal conductivity of a material can be measured directly using laboratory equipment such as a guarded hot plate, which provides steady state thermal conductivity values for the material placed between the plates. The steady-state thermal conductivity data is used to calculate a material’s k value, which is then reported in W m-1 K-1.
The thermal conductivity of a material depends on its type, structure, and state. For example, metals tend to have higher thermal conductivities than plastics and glass due to the delocalized electron movement within their metallic bonding. Liquids and gases have variable thermal conductivity depending on their composition.
While a higher thermal conductivity is generally preferred for applications where rapid transfer of heat is needed, the choice of high or low thermal conductivity ultimately depends on the needs of the application. For instance, in an air-to-air heat exchanger, a high thermal conductivity is ideal because the rapid transfer of heat from the hot surface to the cooler ambient will allow the system to operate at its maximum efficiency.
In addition to calculating a material’s thermal conductivity, it is important to understand its anisotropy for thermal management purposes. Anisotropy refers to the fact that a material can have different thermal properties in each direction. For example, many advanced insulators exhibit anisotropy that allows for more rapid heat flow in one axis compared to the other, a key benefit for efficient energy transfer in aerospace applications. Custom Materials, Inc experts provide a range of experimental metrology services to accurately measure the thermal properties of a wide variety of materials and applications. Contact us to learn more or request a quote today.