Pulse rectifiers silver plating:
Normal silver electroplating machine can’t obtain bright plating coating directly, in order to get brightness need chemical dip or barrel rolling treatment, but will cause silver electroplating coating loss, and difficult to recover 50% of loss, resulting in a greater waste. Bright silver plating can obtain bright plating coating directly, which simplifies operation and reduces waste, but electro plating coating antitarnishing worse, and conductivity deteriorates. Because silver in the air due to the sulfur can easily change color, additives, mostly as sulfur compounds, attached to plating coating inevitably promote its easier to change color, thereby seriously affecting the electrical plating and welding properties. Furthermore, the plating agent attached (in this case the agent can be regarded as impurities) make the silver plating layer impure, electrical properties then decrease. To make an inappropriate analogy, cold medicine to cure a cold, but comes with side effects (such as dizziness, drowsiness, etc.). Bright silver palting solution additives like cold medicine, the use of which may obtain directly bright silver plating layer, but side effects (such as anti-tarnish coating capacity, electrical conductivity variation, additive decomposition products difficult to handle, etc.).
About brightness silver plating side effect problem, the connector industry has been pointed out, the inner and outer conductor of the RF connector using bright silver electroplating, have a greater impact to products environmental resistance and electrical conductivity. In silver plating process also found bright silver plating pieces changing coler fast thant chemical dipping bright or barrel tumbling process type.
Of course, can adopt passivation, immersion silver anti-discoloration agent, or both, and use other measures of bright silver plating coating for anti-color processing, but this is only remedial measures, can not change its attached staff that its nature of sulfur compounds that can cause discoloration or affect other property.
Therefore, if there is high requirements of silver plating coating, generally not advocate the use of bright silver method, some military products (such as aircraft engine bearings protection frame) electroplating silver even prohibited the use of additives. But without additives will not get brightness coating,, while military performance only need the performance not consider brightness, but other products (such as professional electroplating factory processing products) could not deal with like military. Other products even asked for both performance and also the brightness (not using dip or barrel rolling processing) requirements, this is probably some difficulty, it’s something like ask for cold medicine both cure and can not have the side effects.
Some people think of pulse rectifiers silver plating, by using of pulse current in the ordinary silver plating solution to get brightness silver plating coating. Be the case, the pulse current is really an agent both brightness sliver plating and no side effects (good performance) medicine. At first, use a single pulse. Fewer parameters, just turn on, shutdown and peak current, the test soon finished. The result failed, only a single pulse silver plating layer is more detailed than the DC power supply, white, but still dull.
Then consider double pulse. Experts said that if the parameters properly, using double pulse most possible to give a bright nickel plating layer, which in terms of looking for silver-plated medicine is undoubtedly a good news, because if dark nickel-plating use double pulse can be bright, dark silver should be more able to get (anti-cyanide silver plating peel effect is more obvious). But double pulse plating power supply has many parameters, there are positive & negative turn on/off, shutdown and peak current and the positive/reverse working time, and the positive and negative parameters may differ from each other, if all together will be a huge number, so look for a dark silver get bright plating coating were not as simple as a single pulse. At present, dual pulse plating dark silver no matter experiment or production, used commonly parameters, but did not explore deeper, the result certainly will not get bright silver plating. Nevertheless, the double pulse current dark silver-plating get some inspiring results.
It is believed more than one person has done such a test, or have such experience: compare with DC rectifier, single pulse, double pulse dark silver plating machine, DC’s silver no brightness, while single pulse rectifier delicate, white, but still no brightness, and double pulse power supply has clearly brightness (substantially semi-bright) especially in plating parts high area compare to single pulse, and observed other area of workpiece under the sun will be a reflection of light. But this is a result of the use of commonly parameters, commonly parameters may not be the optimal parameters, if the case of optimum parameters, what will happen?
Barrel plating machine tumbling action functions:
① Increase the brightness electroplating layer coating;
② Allows brightness and color more uniform, hanging plating machine type has been got semi-bright in high zone of electro plating parts, why not barrel plating line type can’t obtain whole bright plating layer coating?
Of course, the outcome need facts speak, but adopts double pulse can achieve both performance and brightness at least have the following meanings:
① The use of pulse rectifiers silver plating, double pulse rectifiers with only a small part of plating chemical solution can obtain bright sliver plating coating, which can greatly reduce the amount of additives, to improve plating coating performance (due to attached less additive and pulse plating dense) and as well as ensure brightness, but also saves expensive additives (amplitude usually 50% to 80%);
② If use a common silver plating line, dark silver double pulse rectifiers roll has been got half-bright electroplating coating, then a slight dip bright light treatment shall be bright, by this way, isn’t silver material waste can be reduced?