極易操作的化學鍍鎳染黑劑-遠見化工

Black Nickel-Phosphorus Deposition Process

MetChem BLK-630 is designed to uniformly blacken medium phosphorus electroless nickel parts, easy to make-up and operate at ambient temperature. Produce excellent black oxide surface without risk of over etching on nickel-phosphorus deposition thus black finishing parts perform good corrosion resistance, wearability, and outstanding appearance.


Since beginning of 21th century, the progression of industries and technologies has bloomed intensely. For example, the space exploration and race are not only happened in international competition. Numbers of private space enterprises are growing up and pushing up the requirement of aerospace device and component due to advancement of business satellites. In addition, renewable energy is more popular to become an acceptable solution to power station. Like solar energy, one of the mature renewable technics, not only work by photovoltaics but solar thermal energy therefore lots of photothermal device and absorbing material are applied to commercial solar power. Based on the market of space and renewable energy, the black coating which absorbing solar radiation and thermal effectively plays a key role in aerospace industry, photothermal device, and optical instrument.

In metal finishing, electroless nickel plating provide a high corrosion protective and wear-resisted surface onto parts in area of industrial, electronic, aerospace, and automotive. In late 20th century scientists found a special method to produce exceptionally high light absorption capability on nickel-phosphorus alloys with the appropriate phosphorus content which attacked by an oxidizing acid[1]. This black nickel-phosphorus coating had exhibited awesome features in solar radiation and climate experiment of NASA. Compared to the significant degradation in solar absorptance of black paint resulted from damage to organic chemical bonds or atomic oxygen erosion on the polymeric matrix and carbon pigments, black nickel-phosphorus deposition provides robustness, good absorptance of solar energy, and quickly thermal conduction on-orbit by exposure to the ultraviolet radiation and outgassing due to high vacuum level and atomic oxygen in low Earth. These functional characters fit expectation from industries hence the demand of black electroless nickel is more and more important today.



A typical working solution for job shops to blacken electroless nickel is make-up with strong acids and oxidant including hydrogen peroxide or persulfate. Once the blackness is improper, heating working solution or extending dipping time are common actions. However, the etching on electroless nickel surface will be also aggressively. The surface might be discolored or patterned because of uneven black oxide film, furthermore, thickness of nickel-phosphorus is possible out of low specification by excess etching in working solution.

Fig 1. The chart of comparison between hydrogen peroxide blackener and BLK-630 indicated that the etching rate of BLK-630 was almost half of hydrogen peroxide blackener thus BLK-630 showed more uniform appearance on EN sheet.

MetChem BLK-630 is designed to uniformly blacken medium phosphorus electroless nickel deposition. Make-up with liquid components thus no need a time to dissolve solid component. Rapidly blacken nickel-phosphorus coating at ambient temperature. BLK-630 mildly etch and oxidize nickel surface with almost a half of etching rate of blackener by H2O2. Provide an even black nickel-phosphorus deposition without over etching or even peeling. By using MetChem medium-phosphorus electroless nickel and BLK-630, plate an excellent black nickel-phosphorus coating with good resistance to wearing and corrosion.

Fig 2. The chart of comparison between hydrogen peroxide blackener and BLK-630 indicated that the etching rate of BLK-630 was almost half of hydrogen peroxide blackener thus BLK-630 showed more uniform appearance on EN sheet.

Fig 3. Appearance of black EN parts.


[1]:https://doi.org/10.3847/1538-4365/ab7af8