Hard Anodizing of Aerospace Aluminum Alloys

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• Hard AnodizingofAerospace Aluminum Alloys

Leonid M. Lerner
IMFAIR O9 Royal Air Force Museum, Cosford, UK
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Introduction

• During the twentieth century aluminum became an
  essential metal in the aircraft industry.
  Beginning with the cylinder block of the engine
  that powered the Wright brother's plane at Kitty
  Hawk in 1903, which was a one-piece casting in an
  aluminum alloy containing 8 copper, the use of
  aluminum has grown.

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Burning- rapid catastrophicdissolution of
aluminum during the hard anodizing process

• Watts Amps x Volts Heat Burning

-
-
H
H
Prevention
Prevention
-O2
Air agitation Cooling of electrolyte Organic
additive Correct current
density
H
Sanford Low Voltage DCAC Processes

H
-O2
-O2
 
Al2O3
H
H
-O2
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Our study in Table 1,Columb 10 shows 3.
The Low Voltage DC AC process with organic
additive produced significant energy savings when
compared to HV DC process with organic additive.
The power draw for Low Voltage DC AC (prorated)
was 57 and 137 kWhr/64 (prorated) respectively.
This represents savings of 63 and 22
respectively when compared to HV DC with
additive.
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Comparative Data for Hard Anodizing of 2xxx
Series Aluminum Alloys
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Sanford Low Voltage Process
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Sanford Low Voltage Process
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Uniformity of hard oxide film after Sanford Low
Voltage Process
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Relationship of weight loss with Low Voltage
coating thicknesses for 7075, 6061 and 2024
alloys.
Weight Loss, mg
Thickness, mil
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Dependence of the Low Voltage Hard Anodizing
time upon coating thickness for the three alloys
2024, 6061 and 7075.
Anodizing Time, min
Thickness, mil
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The behaviors of Current during the procedure in
High Voltage Hard Anodizing Process vs. Low
Voltage Hard Anodizing
CURRENT
TIME
CURRENT
TIME
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The behaviors of Voltage during the procedure in
High Voltage Hard Anodizing Process vs. Low
Voltage Hard Anodizing
VOLTAGE
TIME
VOLTAGE
TIME
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Sanford Low Voltage Process
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Sanford Low Voltage Hard Anodizing Processes
Sanford - Quantum Color Hard Anodizing
Sanford Plus Hard Anodizing
Sanford Salvage Hard Anodizing
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