Spectral-directional emittance measurements for 99.99% aluminum, thermally oxidized in air, were performed using a radiometric technique. The apparatus is comprised of a Fourier transform infrared spectrometer and a blackbody-radiating cavity. The sample holder is held on a slotted arc rack, which allows directional measurements from normal to grazing angles. The aluminum sample was heated for an extended period of time (150 h) at high temperature below its melting point prior to performing measurements. The data presented here cover the spectral range between 3 and 14 μm, directional range from surface normal to 72° polar angle, and temperatures from 673 to 873 K. The complex index of refraction is also reduced from emittance data. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and Auger depth profiling were used as surface techniques to characterize the thickness and composition of aluminum oxide film that formed on the metallic surface.
[1]
C. P. Randolph,et al.
The Emissivity of Oxidized Metallic Surfaces
,
1913
.
[2]
S. Gratch.
Advances in thermophysical properties at extreme temperatures and pressures
,
1965
.
[3]
M. Pinar Mengüç,et al.
Thermal Radiation Heat Transfer
,
2020
.
[4]
Design and testing of a high‐temperature emissometer for porous and particulate dielectrics
,
1986
.
[5]
Richard A. Crocombe,et al.
An Infrared Accessory for Studying the Emissivity of Aluminum Surfaces
,
1987
.
[6]
Robert J. Moffat,et al.
Describing the Uncertainties in Experimental Results
,
1988
.
[7]
David G. McLeod,et al.
Spectral-directional emittance of oxidized copper
,
1996
.