The Birth Of Black Electroless Nickel Plating

Electroless black nickel plating is one of the most advanced forms of electroless nickel plating processes that have been formulated in order to finish with a black deposit as it gets processed through the oxidizing acid solution. Generally, electroless nickel alloys are popular because of the beneficial mechanical and physical properties. Black electroless nickel plating is normally used in absorbing materials as well as optical instruments, aerospace industries, and decorative coatings; they are mainly preferred as are the result of their stability against exposure to sunlight, wear resistance in addition to good electrical conductivity.

The black electroless nickel plating is formed through the oxidization of low nickel phosphorous alloys. In comparison to high or medium phosphorous alloys, the black alloy comes with an improved resistance to wear and tear in addition to the deep black finish. This is especially important in terms of appearance as well as the benefits that are associated with a tougher more rugged finish. There we a number of interesting findings that were observed during the process of experimentation at the creation of black electroless nickel plating. It was after a deep analysis that a perfect balance that showed the best immersion time and temperature of the solution that the black electroless nickel plating was actually created. The black color came as a result of the unique surface morphology that integrated with the formation of nickel phosphate and nickel oxides.

Experts tested a number of different etching times for the sulfur, phosphorous, oxygen and the nickel contents; the results indicated that that content of nickel decreased with every increase in the immersion time. This indicated that only the nickel atoms that were in the nodular surface were eliminated permanently while the rest of the nickel atoms went on to form oxides that caused the oxygen and the phosphorous contents to increase at the black nickel surface.

Experts also tested the variation in the intensity of the black finish using different immersion times. At half a minute and one minute immersion times, they noted some iridescence of the black electroless nickel coating. The said iridescence phenomenon was found to have been caused by the nodules that did not completely etch away. When they immersed the black nickel for longer times such as two and five minutes apiece, the black nickel coatings were free from iridescence but with an intense black color. Apart from the intensity of the black color, there was also an observed smoother surface in addition to their being larger nodular structures. Black electroless nickel plating has become a more attractive alternative to the typical electroless nickel plating and is, therefore, the more preferred version these days.