Thermal conductivities of SUS304/PSZ composite materials

The effective thermal conductivity and thermal anisotropy of SUS304/PSZ composite materials produced by three different sample preparation processes have been systematically determined by the laser-flash method in the temperature range from room temperature to 1280K. The results obtained are summarized as follows. 1) The thermal conductivity of SUS304/PSZ composite materials increases with increasing the volume fraction of SUS304. 2) Temperature dependence of thermal conductivity of SUS304/PSZ composite materials also changes with increasing the volume fraction of SUS304. This is attributed to the thermal properties of the components of SUS304(positive) and PSZ (slightly negative). 3) Samples having small fractions of pore show higher thermal conductivity values. 4) The thermal anisotropy is not observed in the samples prepared by sintering at atmospheric pressure. On the other hand, the thermal anisotropy is clearly found in the samples prepared by sintering at 20 MPa. This would be attributed to the preferential orientation of PSZ particles in the direction perpendicular to the direction of applied pressure. 5) Estimation for thermal conductivity values has also been made using the equivalent inclusion method in the composition range with relatively low concentration of dispersed phase, because it is difficult to apply this method to the sample where direct contact between dispersed phases is realized. Fair agreement between the estimated and experimental values was found.