Electric brush as a new surface modification technology, has been in the surface of the new product enhancement, the size of the recovery of wear parts, surface treatment and other aspects of functional special parts are widely used. However, in order to use insoluble anodes is characterized by electrical Brush there are many technical problems, the biggest problem is that in the plating process, the formation of the coating consumed by anodic dissolution of metal ions can not be replenished, as brush work carried out, the bath composition, structure and coating properties are changed. When the bath composition changed to a certain extent, the bath will lose its proper performance. Although the bath still contains metal ions to be plated, but the bath can not continue using it proved , the utilization of the bath is less than 60%.
The reason for using a conventional brush plating technology for high-purity graphite insoluble anode, without using a soluble anode made of coated metal, mainly because of the high anode current density during plating, metal anode is prone to surface passivation, conductive anode deteriorates, even non-conductive, low deposition rate. Therefore, if developed at high anodic current density in the active metal anode remains dissolved state series of plating solution, plating liquid consumption can down 5 to 10 times, significantly reducing costs Brush.
In a wide variety of electrical plating solution, nickel alloy plating solution and consumption biggest. Developed with brush plating solution from nickel and its alloys compensation characteristics, the use of soluble nickel anode instead of the insoluble anode can not only improve the bath utilization, and brush when consumed Ni 2+
Can be obtained from the anode supplement, thereby improving the stability of coating quality, but also can significantly reduce the cost of brush. The key to solving the problem lies, brush plating solution nickel alloy base having a self-compensating characteristics should meet in a very high anodic current density of the nickel anode in the plating solution can normally dissolve surface passivation phenomenon does not occur. However, so far, very few people use electric plating nickel solution truly self-compensating properties. Even electric plating industry is internationally renowned racing to create (Selectron), of gram (Dalic), and Boeing Aircraft Industry Company (Boeing Co.), in the actual electric brush is still used in the production of insoluble anodes. China was made Brush Nickel soluble anode technology, but the use is based on addition of hydrochloric acid and nickel chloride solution, acidic bath, brush when hydrogen evolution serious, prone to hydrogen embrittlement, reducing fatigue performance of high strength steel. In addition, the coating brittle , bath require frequent additional hydrochloric acid to use is its inherent shortcomings.
To this end, Northwestern Polytechnical University successfully developed a series of self-compensation feature neutral nickel-based alloy series electric brush solution (such as Ni; Ni-Co; Ni-Fe; Ni-Co-P, etc.), and using the series bath in the supersonic wind tunnel test section on the surface of a high hardness brush plating, bright nickel-wide grass roots, in other industrial sectors also made a wide range of applications.
By testing full-bright nickel plating bath ultrafast self-compensation feature, the analysis shows that the use of such conduct plating bath can be used as a soluble nickel anodes in the plating process, consumed by Ni plating is formed on the workpiece 2+
By dissolving a nickel anode can be supplemented. Because Ni plating bath 2+
The concentration changes little, so the bath composition is stable, stable coating performance.
Full Bright ultrafast pH of 4.5-5.0 nickel plating bath, a weak acid. Brush when the workpiece or the device may not cause significant corrosion, it will not cause surface passivation of steel parts for coating thickness less Big ((0.3mm) of the workpiece, can not plating layer, can be directly activated after full-bright nickel-Ultrafast can restore size.
For commonly used electrical plating nickel solution, the anodic current density is generally less than 50A / dm 2
, While full-bright nickel plating bath ultrafast operating current density in the range of 50-250A / dm 2
Usually 100A / dm 2
Work up and down, so it is common fast deposition rate of nickel plating 5-10 times a tolerance of 0.2mm repair work (most repairs workpiece dimensions are within the tolerance of the size range) just a few minutes plating time, so not only reduces the labor intensity of workers, but also improve labor productivity.
I selected the company's FJY series since compensation brush technique using metal active anode has more advantages.
1) self-compensating full-bright nickel plating bath having a fast deposition speed, plating thick ability, high coating hardness, easy construction and other features, to overcome the traditional brush plating nickel solution deposition is slow, poor plating thickness, coating quality is not stable drawbacks.
2) using a variety of testing methods for the bath performance is analyzed, tested. The results showed that in the test bath, only the full-bright nickel plating bath ultrafast self-compensation feature, and the performance indicators were higher than General Electric Brush nickel solution.
3) self-compensating full-bright nickel plating bath ultrafast self-compensation feature, so brush significantly reduce the cost, which is about the traditional brush plating Nickel 1 / 5-1 / 10. The technology in key national defense construction projects ( supersonic wind tunnel) in the successful application indicates that the technology can play a greater role in the maintenance of equipment or functional surface treatment.
Supersonic wind tunnel wall nickel oil drilling machinery repair