20.10.2021 by Aileen Sammler, Dr. Natalie Rudolph
Material Science in Additive Manufacturing: Measuring Thermal Diffusivity using LFA
Today, Dr. Natalie Rudolph will explain how the Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity of a powder bed fusion part can be measured using Laser Flash Analysis (LFA) and how it can be computed in Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity.
In the last videos, residual StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress and warpage were investigated using the thermal analysis methods of DMA and TMA. Now, we move to Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity of parts printed with the Additive Manufacturing technology Polymer Powder Bed Fusion (PBF).
This week’s topic: Measuring Thermal Diffusivity using Laser Flash Analysis (LFA)
In the LFA, a light pulse heats the front surface of a plane-parallel sample and the resulting temperature rise at the sample´s rear face is recorded as a function of time. The higher the Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity, the faster the temperature rise reaches the rear face.
Learn about:
- The Laser Flash analysis method and the effects that can be studied with this method
- How fillers enhance Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity
- How to prepare samples for LFA 467 HyperFlash® measurements
- How to compute the Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity of parts printed with Polymer PBF
More Additive Manufacturing applications by NETZSCH
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In our next video, we will talk about the evaluation of refreshing strategy of PBF powder using DSC.