Validation with Inconel 600
Introduction
Inconel 600 is a proven nickel-chromium-iron alloy that is often used as a reference material for determining 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. Its Thermal StabilityA material is thermally stable if it does not decompose under the influence of temperature. One way to determine the thermal stability of a substance is to use a TGA (thermogravimetric analyzer). thermal stability, OxidationOxidation can describe different processes in the context of thermal analysis.oxidation resistance and mechanical strength make it ideal for use in calibration procedures. For this reason, it has been used as a standard material by research institutes for many years. Its ready availability and homogeneous composition also contribute to its suitability as a reference.
The Guarded Heat Flow Meter (GHFM) is best known for determining 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 polymers, but low-conducting metals can also be studied using this technique.
Measurement Conditions
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 was measured using the TCT 716 Lambda guarded heat flow meter (GHFM). In this stationary method, a sample of defined thickness is placed between two plates that are heated to different temperatures. This creates a heat flow through the sample. The heat flow is detected and 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 can be calculated.
Using the TCT 716 Lambda, which allows for simultaneous measurement on two samples, two Inconel 600 samples with a diameter of 51 mm and a thickness of approximately 31.8 mm were analyzed. Prior to the measurement, the samples were coated with silicone grease to improve contact between the sample and the plates and to minimize interfacial resistance. The measurement was carried out simultaneously on both samples in a temperature range between room temperature and 300°C. A pressure of approximately 175 kPa was applied to the samples during the test.
For evaluation of the measurement results, the quartz glass calibration was used.
Table 1: Measurement parameters
| Method | GHFM |
|---|---|
| Calibration material | Quartz glass |
| Samples | Inconel 600 |
| Sample diameter | 51 mm |
| Sample thickness | 31.8 mm |
| Atmosphere | Air |
| Contact pressure | 175 kPa |
| Temperature program | RT to 300°C in intervals of 50 K |
Measurement Results
Figure 1 shows 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 compared to literature data [1]. Both samples are within the expanded measurement uncertainty of approximately 4.8% expected for Inconel 600 [2].
Conclusion
The measurement results confirm that the TCT 716 Lambda Guarded Heat Flow Meter can be used to reliably determine 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, even on low-conducting metals. This underlines the precision and reproducibility of the measurement method, especially in the temperature range under consideration. The data obtained show good agreement with literature values, further confirming the suitability of this method for thermophysical analysis.