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Thermo‐Optical Properties of LaMAl 11 O 19 ( M = Mg, Mn, Fe ) Hexaaluminates for High‐Temperature Thermal Protection Applications
Author(s) -
Liu HongZhi,
Ouyang JiaHu,
Liu ZhanGuo,
Wang YaMing
Publication year - 2011
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2011.04761.x
Subject(s) - emissivity , materials science , ceramic , analytical chemistry (journal) , microstructure , atmospheric temperature range , sintering , mineralogy , chemistry , optics , composite material , physics , meteorology , chromatography
LaMAl 11 O 19 ( M = Mg, Mn, Fe ) ceramics are fabricated by pressureless‐sintering method at 1700°C for 10 h in air. The microstructure and thermo‐optical properties of LaMAl 11 O 19 ceramics are studied by the X ‐ray diffraction, scanning electron microscopy, and F ourier transform infrared spectroscopy measurements. The transition metallic elements such as Mn and Fe at M 2+ site can effectively enhance the emissivity of LaMAl 11 O 19 ceramics at short wavelengths. LaFeAl 11 O 19 has the highest emissivity value of more than 0.8 in the wavelength range of 2.5–6 μm at 500°C. However, the measured emissivity of different LaMAl 11 O 19 ceramics shows a similar trend in the wavelength range of 6–14 μm. LaFeAl 11 O 19 is a promising protective coating material for metallic thermal protection system due to its high emissivity of above 0.7 over the whole wavelength range of 2.5–14 μm at temperatures up to 900°C.