Forbrite BN-200 bright nickel plating process is a newly developed process exhibiting excellent leveling,
brightness and covering power. It also exhibits good
effect on low current density areas.
Ⅰ. Advantages:
1. It produces a bright ductile and good corrosion resistant deposit.
2. Fast deposition rate, low additives consumption.
3. Good throwing power and low current density effect.
4. Excellent leveling property.
5. Deposit is white shade and process has superior tolerance to metallic
impurities.
Ⅱ. Bath compositions and operating conditions :
Composition | Range | Optimum |
Nickel Sulfate |
230-320 g/l | 280g/l |
Nickel Chloride | 40-80 g/l | 60 g/l |
Boric Acid | 35-50 g/l | 40 g/l |
BN-200 | 0.2-0.4 ml/l | 0.3 ml/l |
BN-201 | 2-4 ml/l | 3 ml/l |
WAA | 0.4-0.5 ml/l | 0.5 ml/l |
PH value | 3.8- 4.2 | 4.0 |
Temperature | 50- 60℃ | 55℃ |
Cathode Current Density | 1.0- 9.0 A/dm2 | 5.0 A/dm2 |
Arode Current Density | 1.0- 3.0 A/dm2 | 2.0 A/dm2 |
Agitation | Air or mechanical agitation | |
Filteration | Continuons activated carbon filteation |
Ⅲ. Function of compositon :
1.
Nickel
Sulfate
Nickel Sulfate or Nickel Salt is the priciple source of Nickel ion in plating bath. Under normal circumstances, it is adequate to
analyze the content of nickel metal and nickel sulfate weekly.
2.
Nickel
Chloride
Nickel Chloride increases conductivity allows higher cathode current densities operation, improves low current density deposits
and promotes anode corrosion.
3.
Boric
Acid
Boric Acid content should be maintained at the optimum recommended concentration in order to prevent problems of burning,
high current density exfoliation, orange peel and pitting. It also exerts a beneficial effect on brighteness, ductility and adhesion.
4.
Forbrite
BN-200
Forbrite BN-200 is the secondary addition agent. It should be maintained within the specified range. A low concentration will result
in an overall loss of leveling and brightness.
5.
Forbrite
BN-201
Forbrite BN-201 is the
primary addition agent. Due to its wide permissible concentration range, control
is less critical.
Forbrite BN-201 aids in extending the bright plating range and is essential for good leveling and ductility.
If the concentrations of Forbrite BN-201 is somewhat below the recommended levels it may cause dull deposits in the high current density areas
and may reduce the ampre hour life of Forbrite BN-200.
The brightening agents themselves have certain wetting propenties which, in most cases, should make a wetting agent unnecessary for
air agitated solutions. However, where the design of the parts makes air or gas entrapment a possibility, or in the event of excessive organic
contamination, pitting could occur. In such cases, Forbrite WAA should be employed in a concentration range of 0.5-1.0cc/ l.
The concentration of Forbrite WAA is easily controlled by surface tension analysis using a stalagmometer.
7.
PH
control
It is recommended that the PH of the solution be maintained within the specified range. Lower values cause overall dull deposits and
result in higher consumption of brightener to maintain acceptable work. Higher values of PH tend to promote better brighteness and leveling
but cause precipitaion of iron and other metallics. Values much above 4.5 will be bright and leveled but may reduce the chromium coverage
on somplicated parts.
8.
Temperature
Forbrite BN-200 bright nickel plating process plates catisfactorily anywhere between 50-60℃. At the lower end of temperature range,
slightly more current is required, conversely, higher operating temperature baths have higher bath conductility. Permitting slighthy lower voltage.
For
the highest degree of brilliance and leveling 50-60℃ is recommended.
9.
Filteration
Continuous filteration through activated carbon is essential to insure good quality nickel deposits. Normally, the filter is pre-coated and
then charged with 0.1-0.3 g/l of activated carbon each week.
Forbrite BN-200 process is designed to operate with air agitaion and mechanical agitaion. It permits the use of higher current densities and
produces an infinitely brighter, more level deposits.
11.
Auodes
S-nickel rounds or 1” electrolytic squares in titanium baskets are the most popular due to price, ease of anode replacement or better anode
efficiency. Other types of anodes, such as bar and oval, may be used if desired.
Ⅴ. Maintenance
:
Consumption of Forbrite BN-200 : 7000-1000 A.H./L.
Consumption of Forbrite BN-201 : 5000-8000
A.H./L.
However, the calculation of consumption should depend upon the configuration of articles to be plated the degree of brighteness and
leveling required. Usually, for rough
works surface, higher concentration of Forbrite BN-200 is required.
1. When brighteness and leveling are inadequate, it is required to employ.
Forbrite BN-200 0.3 -0.5 cc/ l
Forbrite BN-201 1-3
cc/ l
2. When cloud deposit in HCD and dull deposit in LCD are founded, it is
required to empoly.
Forbrite BN-201 2-3
cc/ l
3. Purification of bath
(A)
For organic contamination, it is usually treated with continuous
activated carbon filteration or low PH value oxidization.
(B) For inorganic impurities, it is usually treated by higher PH value oxidization or dummy at 0.2-0.5 A/dm2.