Experimental improvements of a four-probe technique to measure the electrical resistivity of molten metals led to an improvement of the measurement uncertainty to less than 6%. Measurements of pure Al and AlSi-, AlSiMg-, and AlSiCu-alloys with a systematic variation of individual components are described. The problem of the calculation of the thermal conductivity has been investigated, and the resulting values of the binary system have been discussed in terms of behavior during melting and solidification. There is a remarkable difference of the thermal conductivity before melting and after resolidification.

Carbon, carbides, and nitrides are materials having a relatively bigh emissivity over the entire spectral range. They are important both as a material and as material components of composites for high-temperature applications, e.g.. in space technology [reusable space transport systems) or energy systcms Ihot gas turbines). The normal total and spectral emissivities of these three materials have been investigated in the temperature range 1000 to 20011K and at wavelengths between 0.6 and 6.8 ./tin. The results have been used to interpret emissivity results of fiber-matrix composites. They are also discussed with regard to potential application as rel~rence materials Ibr high-temperature emissivity meast, rements.

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