Displaying items by tag: phosphorus

Plasma electrolytic oxidation also known as micro arc oxidation (MAO) or spark anodization is a relatively new surface modification technique. The process is used for growing thick, and hard oxide coating on light metals and alloys such as Al, Mg, Ti [1-5]. In principle, the process is similar to anodizing but involves the use of higher voltages and is carried out with mild aqueous alkaline electrolytes [6–17]. In this process, plasma discharge occurs which leads to partial fusion of an oxide film and consequently formation of an extremely adhesive oxide coating on the substrate [18].

Electroless Ni-P coating with subsequent oxidization is a well-established technique for ultra-high absorptance black finish [1–4], although the darkest man-made surfaces are made of carbon nanotubes (CNTs) [5]. The robust surface of the black Ni-P coating is preferable for minimising the risk of accidentally damaging the dimensionally critical baffles of large size. On the contrary the CNT forest is quite fragile. The black electroless nickel has outstanding mechanical properties and stability against sunlight exposure in humid as well as extreme space conditions.