In the present contribution, systematic effective thermal-conductivity measurements with different methods are reported for various materials. One of the materials studied, calcium silicate, is isotropic; the other two, alumino-silicate and alumina fiber mats, are non-isotropic. The measurements were carried out with two different steady-state panel test apparatus (according to ASTM C201, designed and constructed by authors), two guarded hot-plate apparatus (ISO 8302, with either one or two samples), one steady-state radial heat flow apparatus (designed by authors), and one transient hot-wire instrument (DIN EN 993-14). These apparatus are operated at ambient pressure and atmosphere (air) between 20 and 1,650 • C, and are briefly described in the article. The results show the well-known increase of effective conductivity with temperature, mainly due to radiation heat transfer. For the case of the isotropic calcium silicate material (bulk density of 220 kg m −3 ), no significant differences between the various methods have been found and the results can easily be correlated within ±10%. The fiber-mat results, however, show additional effects of the density (between 103 and 170 kg m −3 ) and the fiber orientation. Large differences exceeding 30% are found between plate and hot-wire results.

The results of an inter laboratory comparison of thermal conductivity, thermal diffusivity, specific heat capacity, and thermal expansion measurements on austenitic stainless steel in the temperature range between 20 and 1000 • C are presented here. Mean values are presented for the physical properties studied. Reliable relative expanded uncertainties can be stated for the properties determined, which were achieved by applying good measurement practice, i.e., 3% for thermal expansion, 5% for specific heat capacity and thermal diffusivity, and 6% for thermal conductivity. The mean values derived from this intercomparison agree well with the results of a previous intercomparison in 1990.

A new steady-state panel test facility is presented which has been designed and constructed for effective thermal-conductivity measurements of insulations in the temperature range between 300 and 1,650 • C following ASTM C201-93 and DIN V ENV-1094. Square-shaped samples (length of 400 mm) are used, heated from above and settled on a water-cooled calorimeter system to obtain a one-dimensional steadystate temperature field. The heat is supplied by electrical heating elements freely hanging inside a furnace which is completely constructed from ceramic components to withstand temperatures up to about 1,800 • C. The calorimeter system consists of a square central measuring zone (length of 100 mm) surrounded by guard loops to avoid heat losses in all directions. The samples, e.g., a number of fiber mats, one on top of the other up to a maximum height of 110 mm, are open to ambient pressure and atmosphere (air). Measurements include the heat flow rate (taken in the central calorimeter), temperature differences across individual layers of the sample (measured by a series of thermocouples which regularly have to be calibrated), and the thickness of the respective layers (before and after the experiment). The thermal conductivities range from 0.025 to 2 W · m −1 · K −1 , and both isotropic and non-isotropic materials can be investigated due to the one-dimensional characteristic of the temperature field. Measurements for alumina fiber mats are presented, and good agreement is found with respective results from other methods and test facilities.

High-temperature thermal conductivity of insulating material is usually measured by application of the steady-state calorimeter method or the transient hot-wire method. However, when applied to non-isotropic materials, the methods yield results which show systematic differences depending on orientation of the material during the measurement. In this contribution results are presented for one and the same material measured between room temperature and 1300 8C in all three instruments (according to the steady-state plate, the steady-state cylinder, and the transient hot-wire methods). Additional experiments are carried out in these instruments with various fibre orientations. Differences between the measured conductivities are found to exceed 100% in the high-temperature range. The results are discussed and supplemented by raster electron microscope (REM) and differential thermal analysis (DTA) of the fibre material and numerical studies of the temperature fields inside the facilities.

There is a variety of components, which are subject to high wear and/or corrosion stress on the one hand and are used to transfer heat on the other hand. Two examples are drying cylinders in paper production and condensing boilers. Up to now there are no data available for the thermal design of thermal spray coated components except for some MCrAlY and thermal barrier coatings for turbine applications. Also guidelines for the optimization of thermally sprayed coatings concerning heat transfer including the effect on the wear resistance are missing. HVOF sprayed cermet coatings are widely used for combined wear and corrosion protection these days. In addition to WC-CoCr 86 - 10 4 and 75 Cr3C2 - 25 Ni20Cr conventional Ni5Al and Ni20Cr bond coats are evaluated concerning their thermal conductivity in the range between room temperature and 600 °C. Also the thermal contact resistance is determined depending on the substrate material: mild steel S355J2G3 (1.0570), grey cast iron GG25 (0.6025) and austenitic stainless steel X5CrNi18-10 (1.4301, AISI 304). The applied Laser- Flash method requires knowledge of the heat capacity, thermal expansion and density, which are determined before. HVOF spraying has only negligible influence on the heat capacity of WC-CoCr feedstock, as the temperature depending functions are almost identical. The use of spraying feedstock with average WC particle sizes of 800 nm, 3 µm and 5 µm permits to investigate the influence of the specific surface area of the hard phases both on the thermal conductivity and wear resistance. Furthermore the influence of the coating porosity is determined. In accordance to the drying cylinder application the wear resistance is determined by Taber-Abraser wear tests. Bond coats are produced by HVOF, HVCW and arc spraying and compared concerning microstructure and thermal conductivity. A comparison to the properties of electroplated hard chromium coatings is drawn.