Characteristics of brush plating technology

       The basic principle of brush plating technology is similar to that of tank plating, but it has many characteristics that are different from tank plating. It is these characteristics that bring a series of advantages to the brush plating technology, making it stand out in the surface engineering. The main features of brush plating technology can be described from three aspects.



1. Equipment Features



Most of the electric brush plating equipment is portable or mobile, small in size and light in weight, which is convenient for on-site use or field repairs. Neither a plating tank nor a hanger is required, and the number of equipment is greatly reduced. The occupied space is also small, and the equipment requirements on the site facilities are greatly reduced. A set of equipment can complete the brush plating of various coatings.



The pen-plating (anode) material is mainly made of high-purity fine graphite, which is an insoluble anode. The shape of graphite can be made into various styles according to the needs to adapt to the surface shape of the workpiece to be plated. When brush plating some baths, metal materials can also be used as anodes.



The electricity and water consumption of the equipment is much less than that of tank plating, which can save energy and resources.



2. Characteristics of plating solution



Most of the brush plating solutions are aqueous solutions of metal-organic complexes, which have considerable solubility in water and good stability. Therefore, the content of metal ions in the plating solution is usually several times to tens of times higher than that in tank plating.



Different plating solutions have different colors, transparent and clear, without turbidity or precipitation, which is easy to identify.



It has stable performance and can be used in a wide range of current density and temperature, and it is not necessary to adjust the concentration of metal ions during use.



Non-flammable, non-explosive, non-toxic, most plating solutions are close to neutral and less corrosive, so it can ensure the safety of manual operation, and is also convenient for transportation and storage. Except for individual plating solutions such as gold and silver, no toxic complexing agents and additives are used. Now cyanide-free gold plating solution has been developed.



The successful development of the plating solution curing technology and solid preparation has brought great convenience to the transportation and storage of the plating solution.



3. Process characteristics



The biggest process feature of brush plating that is different from electroplating (tank plating) is that the plating pen and the workpiece must maintain a certain relative movement speed. It is because of this feature that it brings a series of advantages to brush plating.



Due to the relative movement between the plating pen and the workpiece, the heat dissipation conditions are good, and the workpiece is not easily overheated when brush plating with a high current density is used. The formation of the plating layer is an intermittent crystallization process, and the metal ions in the plating solution are only discharged and reduced to crystallize at those parts where the plating pen contacts the workpiece. The movement of the forging pen limits the growth and arrangement of grains, so there are a large number of ultra-fine grains and high-density dislocations in the coating, which is an important reason for the strengthening of the coating.



The plating solution can be sent to the surface of the workpiece in time with the plating pen, which greatly shortens the process of metal ion diffusion, and is not easy to produce metal ion depletion. In addition, the high content of metal ions in the bath allows the use of much higher current densities than in tank plating, resulting in faster deposition of coatings.



Manual operation is convenient and flexible, especially for complex surfaces, any place that can be touched by a plating pen can be plated, which is very suitable for on-site repair of large equipment without disassembly.