Emissivity Qualification Comparison

 

Emissivity Article: Understanding Emissivity: Through the Looking Glass.

Through the Looking Glass

Emissivity Qualification Comparison performed by a major aerospace company involving three plating suppliers and six different substrates
Low Emissivity Gold Plating Vendor and Targeting Hemispherical Emissivity of < 0.04

 

Substrate
Epner Emissivity (Hem)
Company B Emissivity (Hem)
Company C Emissivity (Hem)
 
1100 Al- Side A
0.023 0.027 0.036
1100 Al- Side B
0.017 0.030 0.036
1100 Al- Side A
0.031
1100 Al- Side B
0.034
_________
__________ ________ ________
Average
0.02 0.0305 0.036
6061-T6 Al-Side A
0.021 0.018 0.021
6061-T6 Al-Side B
0.014 0.018 0.021
6061-T6 Al-Side A
0.027
6061-T6 Al-Side B
0.021
_________
__________ ________ ________
Average
0.0175 0.021 0.021
6063-T6 Al-Side A
0.029 0.011 0.029
6063-T6 Al-Side B
0.02 0.011 0.031
6063-T6 Al-Side A
0.014
6063-T6 Al-Side B
0.014
_________
__________ ________ _________
Average
0.0245 0.0125 0.03
Beryllium – Side A
0.023 0.041 0.043
Beryllium – Side B
0.016 0.044 0.031
Beryllium – Side A
0.022 0.039 0.037
Beryllium – Side B
0.017 0.044 0.037
_________
__________ ________ _________
Average
0.0195 0.042 0.037
Titanium 6Al4V – Side A
0.049 n/a 0.032
Titanium 6Al4V – Side B
0.020 n/a 0.032
Titanium 6Al4V – Side A
n/a n/a n/a
Titanium 6Al4V – Side B
n/a n/a n/a
_________
__________ ________ ________
Average
0.0345 n/a 0.032
Titanium 1581
n/a 0.031 n/a
Titanium 1581
n/a 0.030 n/a
Titanium 1581
n/a 0.025 n/a
Titanium 1581
n/a 0.021 n/a
_________
__________ ________ ________
Average
n/a 0.02675 n/a
Vendor Scores – Sum of Average Emissivitys (lowest is best)

0.1160

0.1328

0.1560

Company B
Best Titanium Vendor. Best 6063 Aluminum, Excellent 1100 and 6061 Aluminum. Failed Beryllium
Company C
Overall, highest emissivities (higher risk to processes). Passing for Aluminum and Titanium. Failed Beryllium
EPNER
Overall, lowest emissivities (lowest risk to processes), Best 1100 and 6061 Aluminum Vendor, Excellent Beryllium. Failed Titanium, may be due to substrate.
Failing Criteria
A single Measurement exceeding 0.04