Nickle Electroplating Common Problems

1, pinhole, pitting and peeling

Continuous electroplating with pinholes, pits and peeling are the most common faults in electroplating, mainly due to the following reasons.

(1) continuous plating heat treatment process improper

In the process of mechanical processing, parts of the surface of the anti-rust grease, cutting fluid, mechanical oil, lubricating grease, grinding fluid, release agent and dust, polished dust mixed together to form a thick dirt. If the above heat treatment does not remove the above dirt, then the quenching and sintering into a stubborn solid grease after degreasing rust is difficult to clean, plating the bubble attached to the formation of gas on the formation of gas retention hole.

(2) poor pretreatment of Nickle Electroplating plating

Heat treatment of the workpiece surface will inevitably adhere to a layer of oil, when the dust fell on the surface, and mixed with grease together, a long time it is difficult to clean, so that the surface of the workpiece to form a small oil spots, When the bubbles remain on the formation of pinholes. In addition, the use of mesh belt resistance furnace quenching, the workpiece surface oil and dust and other impurities mixed with particles, sintered into a stubborn solid grease, nitrate salt tempering, the above grease and nitro salt and the formation of stubborn thermal polymer , The plating is difficult to completely remove the above dirt, hydrogen bubbles easily adhere to the dirt above, it is difficult to discharge, so that the coating pinhole and pitting phenomenon, and with the bubble gradually grow, the coating will automatically burst , Resulting in peeling phenomenon.

2, the coating from the skin off

There are two possible causes of such failures, one is poor coating and substrate adhesion, and second, Nickle Electroplating layer of brittle, ductility is small.

If the improper heat treatment is difficult to remove the dirt or pre-treatment is not complete, dirt mixed between the matrix and the coating, so that the coating and the substrate binding is poor, follow-up assembly processing, easy to peel off.

When the brightener with improper or poor quality, pH is too high, the cathode current density is too large and the bath temperature is too low, will cause hydrogen ions in the cathode reduction, then the state of hydrogen into the matrix metal and coating, So that the base metal and coating toughness decreased and produce "hydrogen embrittlement" phenomenon. In addition, when the Nickle Electroplating liquid metal impurities and decomposition products too much, but also make the coating "hydrogen embrittlement" phenomenon.

3, poor corrosion resistance

Since the porosity of the Nickle Electroplating-plated layer is high, it is substantially non-porous only when the coating thickness exceeds 25 microns. Therefore, the thin nickel plating layer can not be used alone as a protective coating, it is best to use double nickel and multi-layer nickel system.

4, hanging green corrosion

After the use of VCF a 385 anti-rust cutting fluid on the coating closed treatment, when the rust-proof cutting fluid after drying, the product will be formed on the green phenomenon of hanging green.

5, the hole exposed copper

As the bright nickel plating solution of the deep plating capacity is not as good as cyanide plating dark copper, electroplating after the bright nickel coating in the product hole parts can not completely cover the copper coating, it caused the product hole exposed copper bad phenomenon.