Heat Diffusion

Diffusion is one of the most important concepts in Materials Science and Engineering. Both mass and heat diffusion are a function of time and position inside the material, and can be described by similar kinetic equations. Here, we are investigating the flow of heat through the material, or how the temperature changes. Two methods are used to do this: the so-called “flash” method using the pyroelectric detector, and the Angstrom method. In both cases, a thermal diffusivity can be calculated and compared to literature values.


Equipment Used

  • Halogen lamp, Optical chopper, and Pyroelectric Detector
  • Lock-in Amplifier with accompanying 5105 Acquire software by Signal Recovery
  • Digital oscilloscope with EasyScope software
  • Neutral density filters
  • Breadboard with connected thermocouples
  • Flexible resistance heaters
  • Validyne data acquisition system with accompanying EasySense software
  • Calipers and rulers

Materials Tested

  • Discs of graphite, silicon, alumina, or steel (for Flash method)
  • Rods of copper, silicon carbide, silicon nitride, alumina, or aluminum nitride (for Angstrom method)