CHROMATE CONVERSION COATINGS
Chromate conversion coatings are used widely in the metal
finishing industry. These coatings can be applied to deposits
of zinc, cadmium, copper alloys and silver. Chromate conversion
coatings can also be applied to aluminum, zinc die castings,
and magnesium substrates.
These conversion coatings convert the metal surface to a
superficial layer containing a complex mixture of chromium
compounds. This superficial layer will provide a barrier between
the environment and the deposit or substrate surface, thus
extending the corrosion resistance.
Colors vary from clear or blue-bright, yellow, olive drab
or green, and finally black. These films can also be dyed
a variety of colors. The corrosion protection provided by
various conversion coatings is outlined below.
CHROMATE CONVERSION COATINGS
|
Deposit or Substrate
|
Color Desired
|
Product
|
|
Aluminum
|
Clear
|
A-141-PC
|
|
Aluminum
|
Yellow
|
PAC®-850
|
|
Brass
|
Clear
|
PD-20
|
|
Cadmium
|
Clear
|
Aftr Glo® 121C
|
|
Copper
|
Clear
|
PD-20
|
|
Silver
|
Clear
|
PD-20
|
|
Zinc Die Casting
|
Yellow
|
ZDP-92
|
|
Deposit
|
Color Desired
|
Description
|
ASTM B-117 N.S.S.
Hrs to 5% WC
Barrel
|
ASTM B-117 N.S.S.
Hrs to 5% WC
Rack
|
Product
|
|
Zinc
|
Blue Bright or Clear - Powder
|
Conventional -
No Nitric Added
|
8 - 15
|
12 - 24
|
Aftr Glo® PBS
|
|
Zinc
|
Blue Bright or Clear - Liquid
|
Conventional -
Add Nitric
|
8 - 15
|
12 - 24
|
Aftr Glo® PN220
|
|
Zinc
|
Blue Bright or Clear - Liquid
|
Conventional
Trivalent
|
8 - 15
|
12 - 24
|
188
|
|
Zinc
|
Blue Bright
|
High Protection Trivalent
|
24 - 72
|
75 - 125
|
TP105
|
|
Zinc
|
Blue Bright
|
Ultra High Protection Trivalent
|
48 - 96
|
100 - 250
|
HI TEST™
CC-3
|
|
Zinc
|
Blue Bright
|
Ultra High Protection Hexavalent
|
40 - 80
|
200 - 400
|
SAPPHIRE® 325
|
|
Zinc
|
Yellow
|
Conventional
|
50 - 96
|
75 - 144
|
Aftr Glo® 529
|
|
Zinc
|
Yellow
|
High Protection
|
75 - 150
|
150 - 250
|
TOPAZ™ HC
|
|
Zinc
|
Yellow
|
High Protection Trivalent
Single-Step
|
24 - 72
|
72 - 96
|
TP105 w/
HI TEST™ YT
|
|
Zinc
|
Yellow Trivalent
|
Ultra High Protection Trivalent
Single-Step
|
48 - 96
|
100 - 150
|
HI TEST™ CC-3 w/
HI TEST™ YT
|
|
Zinc
|
Olive Drab
|
Conventional
|
50 - 150
|
100 - 200
|
OLIVE HT
|
|
Zinc
|
Dark Olive Drab
|
Ultra High Protection
|
300 - 500
|
350 - 550
|
OLIVE HT w/
EB 502
|
|
