ANALYSIS OF LOCAL HEAT-TRANSFER PROPERTIES OF TAPE-CAST ALN CERAMICS USING PHOTOTHERMAL REFLECTANCE MICROSCOPY

Photothermal reflectance microscopy was applied to the analysis of loc al thermal diffusivity on tape-cast AIN ceramics. The materials were o btained from three different commercial powders, two sintering tempera tures (1750 and 1800 degrees C), and 3 wt % Y2O3 sintering aid. Owing to the high spatial resolution of the technique (similar to 30 mu m in the present case), measurements in different positions on the sample surface were carried out. In this way a study of the homogeneity of th ermal properties was performed.