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YELLOW BRONZE is an alkali copper - tin - zinc cyanide
plating system, designed to deposit an alloy of 78% Cu, 16% Sn
and 6% Zinc. The deposit produced is hard, with a yellow - gold
2 N Color over a wide range of operating conditions. Because of
its exceptional properties yellow bronze solution may be used as
both final finish or pre gold undercoat. Used as under coat, it
provides:
An improvement in brightness and reflectivity of
work piece with better corrosion properties .
A reduction in thickness of gold , while
preserving the yellowness of gold even after wear .
A replacement for Nickel , which often causes
allergies and not permitted in certain applications .
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Yellow Bronze and
white
bronze
plated emblems |
Yellow Bronze
plating
over nickel plated ring |
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Yellow bronze
plated rings with
gold flash coating |
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Yellow bronze may also be
used as a final finish, where it is a suitable imitation gold
for bathroom fittings, furniture hardware etc where cost of
precious metal plating is prohibitive. By varying the alloy
composition white bronze can be plated. It is very good
replacement for nickel plating.
The yellow bronze process is a
very stable and easy to control .
DEPOSIT CHARACTERISTICS:
Alloy
Composition - copper - 78%, zinc - 6%, tin
- 16%
Appearance - bright, even gold
color close to 2N
Hardness
- 250 - 350 HV
Ductility
- excellent
Density
- 8.5 (1 um/dm2 of alloy weight approx. 85 mg)
MAKE UP:-
The yellow
bronze solution is supplied as ready to use solution. Fill the perfectly cleaned PP tank with
yellow bronze to working level.
Heat to 45 0C
. The bath is now ready to work.
OPERATING CONDITIONS :-
Parameters
Optimum
Range
Bath density (on
make up )
1.133 1.112 - 1.13
PH
12.7 12.4 - 13.0
Temperature
0C
45 39 - 47
Cathode current
density (A/dm2) 1.5
0.5 - 3.0
Cathode
Efficiency 15 - 18
mg/A/min
Agitation
Cathode movement
Anodes
Pure Graphite or stainless steel.
Deposition
Speed 0.4 Um/min at 1.5
A/dm2
Equivalent to 1um in 2.5 minute
EQUIPMENT:
Tanks should be
made from PP or high density polyethylene .Rectifier should be
fitted with continuous current regulation and ammeter suitable
for the surface area to be plated and either an ampere hour or
ampere minute meter. The ripple should be less than 5% Immersion
heaters should be sheathed with porcelain; quartz of PTFE
Thermostatic control should be within +/- 10C
.Filtration should be magnetically coupled pump and PP filters
with 5-micron filter cartridge must be used. The pump rate
should be 3 - 5 tank turn overs / hour .Agitation may be back
and forth cathode bar movement at 5 - 8 m / min or by
alternating, controlled speed circular motion .Anodes should be
nuclear grade pure graphite The anode surface area should be at
least double of cathode area. Don't use anode bags . Due to
presence of Cyanide in bath, efficient fume extraction must be
fitted.
We supply chemicals and equipments required for yellow bronze
plating. Now yellow bronze plating is used for jewellery,
hardware and decorative items. We give complete technical
service to start your bronze plating. We have all laboratory
specialties to control all parameters required for good yellow
bronze plating.
If
you want to start an bronze plating
contact us
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