Combined DSC and Pulse-Heating Measurements of Electrical Resistivity and Enthalpy of Platinum, Iron, and Nickel

Abstract

Measurements of the enthalpy, electrical resistivity, and specific heat capacity as a function of temperature starting from the solid state up into the liquid phase for Fe, Ni, and Pt are presented. Two different measurement approaches have been used within this work: an ohmic pulse-heating technique, which allows -among others -the measurement of enthalpy, specific heat capacity, and electrical resistivity up to the end of the stable liquid phase, and a differential-scanning-calorimetry technique (DSC) which enables determination of specific heat capacity from near room temperature up to 1500 K. The microsecond ohmic pulse-heating technique uses heating rates up to 10 8 K·s −1 and thus is a dynamic measurement, whereas the differential-scanning-calorimetry technique uses heating rates of typically 20 K·min −1 and can be considered as a quasi-static process. Despite the different heating rates both methods give good agreement of the thermophysical data within the stated uncertainties of each experiment. Results on the metals Fe, Ni, and Pt are reported. The enthalpy and resistivity data are presented as a function of temperature and compared to literature values.

Combined DSC and Pulse-Heating Measurements of Electrical Resistivity and Enthalpy of Tungsten, Niobium, and Titanium

“…The temperatures covered by the different optical pyrometers range from 1200 K up to about 5000 K, depending on the actual emissivity of the material under investigation [3]. Thus, the lower temperature limit of the pyrometer of the pulse-heating experiment is also due to the use of a neutral density filter and reaches about 1700 K for titanium and niobium, and about 2300 K for tungsten.…”

“…This issue has already been discussed extensively in Ref. 3. To overcome this limitation and to obtain temperature dependences for these quantities below the onset temperature of the pyrometers, a differential scanning calorimeter (Netzsch DSC 404) was added to our setup and incorporated into the basic measurement routines for data in the temperature range of about 500-1500 K. The DSC is basically designed and used for accurate specific-heat-capacity measurements in the above mentioned temperature range.…”

Thermophysical Properties of Five Binary Copper–Nickel Alloys

“…A simple binary alloy system (copper-nickel) with a small melting range and complete miscibility was chosen for this work to investigate different concentrations and to compare the results to properties of both pure elements, which have been extensively investigated by different authors [2][3][4]. The samples were die-cast and drawn to wires of 0.5 mm in diameter.…”

“…Specific enthalpy of five Cu-Ni alloys, pure copper[2,3], and pure nickel[4] as a function of temperature; numbers refer to mass% nickel, dashed line: 1750 K (seeFig. 2) Specific enthalpy of five Cu-Ni alloys, pure copper[2,3], and pure nickel[4] at 1750 K (as indicated by the dashed line inFig.…”

“…2) Specific enthalpy of five Cu-Ni alloys, pure copper[2,3], and pure nickel[4] at 1750 K (as indicated by the dashed line inFig. 1) as a function of nickel content; solid line: Specific heat capacity of five Cu-Ni alloys, pure copper[2,3], and pure nickel[4] for the liquid phase as a function of nickel content; solid line: linear interpolation according to Kopp-Neumann rule…”