Research On Infrared Radiation Characteristics Of High-emissivity Coating

Researching on the infrared radiation characteristics of coating is the research on the infrared spectral emissivity of coating in fact. The infrared spectral emissivity is the most important parameter of infrared radiation characteristics. Researching on the infrared spectral emissivity have not only an obvious scientist meaning, but also an important project application value, it is widely used in the area of industrial production, national defense and military, infrared stealth, aerospace, temperature measurement technique, et al.The infrared spectral emissivity measurement is precision measurement, the precision of the measurement devices relates to the reliability of the measurement results. This essay is based on the FTIR, it has evaluated the thermal radiation characteristic of the blackbody radiation source in the infrared spectral emissivity measurement devices, and it also has calibrated the FTIR spectrometer at the temperature range 373~973 K in the wavelength range 2~14 μm through the piecewise linear calibration. The evaluation results indicate that the infrared spectral emissivity of the blackbody radiation source is nearly 1, and it can be used as a calibrated radiation source in the spectral emissivity measurement devices.Pyromark1200 is a type of high-temperature high-emissivity coating. Its stably working condition is at the temperature range 589~922 K. It is the coating of the inner wall of the heat pipe in the traceability system for the blackbody radiator of our country. Its accurate characterization of infrared spectral emissivity has an important meaning to the radiation temperature measurement of our country. Data on infrared spectral emissivity of Pyromark1200 is in shortage, as well as the reports on its infrared radiation characteristics affected by its spray painting process, microstructure and thermal process. The results of this research show that:(1) Through measurements, the normal infrared radiation characteristic is analyzed within the range at the temperature range 573~873 K under normal atmospheric condition and the total infrared spectral emissivity of Pyromark1200 coating is higher than 0.93 in the 3~14 μm wavelength range.(2) The coating film critical thickness on the metal base is 10μm according to comparison among different types of spray painting process, coating film thickness, microstructure, which would influence the infrared radiation characteristics of Pyromark1200 coating. The infrared spectral emissivity will attenuate when the coating film thickness is lower or much higher than that.(3) The result of 72-hour aging test at the temperature 673 K which studied the effect of thermal processes on the infrared radiation characteristics of the coating shows that the infrared spectral emissivity variation range is approximately 0.01 indicating that Pyromark1200 coating is with good stability. Pyromark1200 is suitable for spraying on the material surface which is in long-term operation under high temperature work conditions and requires high infrared spectral emissivity.