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Plating knowledge (III)

Release time:

2024-01-08

Source:

Many types of chrome plating process, according to its use can be classified as follows.

① protection a decorative chrome plating: protection a decorative chrome plating commonly known as decorative chrome, thin coating, bright and beautiful, usually as the outer layer of multi-layer plating, in order to achieve the purpose of protection, in the zinc-based or steel substrate must first be plated with a thick enough intermediate layer, and then in the bright intermediate layer plated with 0.25 ~ 0.5μm thin layer of chromium.

② hard chromium plating (wear-resistant chromium) coating: with high hardness and wear resistance, can extend the service life of the workpiece, such as cutting and drawing tools, various materials of the press mold and mold, bearings, shafts, gauges, gears, etc., can also be used to repair the dimensional tolerances of worn parts.

③ milky white chromium plating chromium plating layer: milky white, low gloss, good toughness, low porosity, soft color, hardness than hard chromium and decorative chromium low, but high corrosion resistance, so commonly used in measuring tools and instrument panels. In order to improve its hardness, the surface of the milky white coating can be plated with a layer of hard chromium, the so-called double-layer chromium coating, which has the characteristics of milky white chromium plating and hard chromium plating, and is mostly used for plating parts that require both wear resistance and corrosion resistance.

The plating of loose hole chromium (porous chromium): is the use of chromium layer itself has the characteristics of fine cracks, after hard chromium plating and then mechanical, chemical or electrochemical treatment, so that the crack network to further deepen and widen. The surface of the chromium layer is covered with wide grooves, which not only has the characteristics of wear-resistant chromium, but also can effectively store lubricating medium, prevent non-lubricating operation, and improve the anti-friction and wear ability of the surface of the workpiece. It is often used to coat the surface of sliding friction parts under heavy pressure, such as internal combustion engine cylinder cavity, piston ring, etc.

Black chrome black chrome plating: black, with uniform luster, good decoration, with good extinction; high hardness (130 ~ 350HV), wear resistance in the same thickness than bright nickel 2~3 times higher; its corrosion resistance and ordinary chrome plating the same, mainly depends on the thickness of the intermediate layer. Good heat resistance, will not change color below 300 ℃.

Key words:

Factors affecting the surface roughness of the workpiece surface after chromium plating

Chrome plating, a process that makes metal shiny!

Factors affecting the surface roughness of the workpiece surface after chromium plating

Chrome plating, a process that makes metal shiny!