RADIATING CAPACITY OF METAL-CERAMIC COATINGS

Results are reported from studies into the radiating capacity epsilon(lambda) (monochromatic emissivity factor at the wavelength lambda = 0,65 mm) of metal-ceramic Mo-Al2O3 coatings with a Al2O3 20,5 % wt, Al2O3 concentration at temperatures between 1300 K and 2200 K. It is found that the radiating capacity of coatings inder study starts to decrease with an increase in the temperature from 1400 K (epsilon(lambda) =0,98 at 1400 K), reaching its minimum at 1600 K (epsilon(lambda) = 0,83). With a further rise in the temperature, epsilon(lambda) increases and at 2200 K. it attains 0,96...0,97. It is also demonstrated that the reflection of coatings with 20 to 30 wt. % Al2O3 content reaches 7 to 8 % at room temperature for lambda = 0,4...0,8 mu..