Cast iron workpiece in the use of alkaline zinc-nickel alloy additives due to its processing special, complex structure, and cast iron surface is easy to rust, rust is difficult to deal with, poor decorative, so in the plating process need to improve its surface properties. For the special characteristics of cast iron, these 3 points should be noted when plating:
1. Cast iron surface in the high temperature casting process will form a layer of non-conductive oxide film, will hinder the deposition of zinc-nickel alloy plating. Therefore, the oxide skin on the surface of the workpiece should be thoroughly removed before plating. Bigelow suggests the use of shot blasting machinery to polish the surface, not only can effectively remove the oxide skin, but also can make the casting of the formation of high carbon layer off, resulting in microscopic roughness, which is conducive to improving the bonding of the plating layer.
2. Cast iron substrate structure is loose and porous, there will be a large number of in the trachoma, loose surface, uneven, so the surface area will be much larger than the macro-area, resulting in the actual current density will be much smaller than the performance of the current density, so in the zinc-nickel alloy plating process the current density should be greater than the other steel substrate 1 to 2 times. The surface is instantly activated by the impact of high current in order to make the loose surface covered by dense plating.
3. Acid washing and ultrasonic cleaning process should be strengthened. As cast iron parts in the process of processing will leave a lot of grease, lubricating oil and freezing liquid, as well as from the casting mold residual sand and iron filings in the storage process will generate oxide film and other insoluble pollutants, and cast iron itself contains a large number of graphite, so in the zinc-nickel alloy plating should be strengthened in the pickling and ultrasonic cleaning and other pre-treatment processes, in order to form a uniformly clean, conductive, easy to plating of the zinc-nickel alloy Plating layer.
About us
Guangdong Bigely Technology Co., Ltd. ,founded in 2003, is a high-tech enterprise integrating R & D，production, sales and service, specializing in the production of electroplating additives. As a famous electroplating additives source manufacturer in China, Bigely has over 20 years' experience in electroplating additives production and own production base of 5000 square meters. We can produce 15,000 tons of electroplating additives every year, which can fully meet the needs of customers.
If you need our high-quality electroplating additives, please contact us. We can provide you samples for test, and also provide a series of services.
