BEHAVIOR OF THERMAL-RADIATION PROPERTIES OF OXIDE CERAMICS UNDER SUBSECOND LASER-HEATING

It is shown that the data on spectral emissivity and reflectivity obtained in sub-second laser heating experiments differ from values which are obtained by the conventional methods. Owing to the semitransparency of oxides, these thermal radiation properties depend on the temperature distribution in near-surface layers and cannot be related to a definite temperature value. The condensation of the products of oxide evaporation at high temperatures, which takes place in air surrounding a sample, may affect the measurement of temperature, reflectivity, and emissivity.