Metale i Stopy
Pure Copper - Thermal Diffusivity
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 pure copper was measured for both the heating and cooling cycles.
The large change in the thermal diffusivity at approximately 1080°C is due primarily to the change in the electronic component of 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 upon melting or solidification. The fact that there is almost no difference in the thermal diffusivity values between the heating and cooling cycles indicates that no significant microstructural changes occurred. The measured values of the thermal diffusivity for both the solid and liquid regions deviated from those found in the literature by less than 2.5%. Note that the change in thermal diffusivity provides a good temperature calibration point for the LFA (Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).melting point of pure copper = 1083°C). (measurement with LFA 427)