Flat solar collector is a good blue film, or good black chrome? It is best to specify.
However, the current plating black chrome process, the current density (15 ~ 200A / dm2), the solution conductivity is poor, plating will produce a lot of Joule heat, cooling and ventilation need to maintain normal production. In addition, the black chrome plated in the non-copper pieces, you need to pre-copper, and then plating bright nickel, and finally black chrome, the higher production costs.
Black nickel coating is mostly nickel alloy coating, its composition with the plating solution composition and deposition conditions change. Black nickel plating solution is divided into two categories, namely zinc sulfate plating solution and molybdenum-containing plating solution. The black nickel coating obtained from the first type of bath contains 40% to 60% nickel and about 20% to 30% zinc.
The absorption ratio α and the emission ratio ε of the black chromium coating are 0.93-0.97 and 0.07-0.15, respectively, and α / ε is 6 to 13, and has excellent spectral selectivity.
Black chromium coating thermal stability and high temperature performance is also very good, suitable for high temperature conditions, at 300 ℃ long-term stable operation. In addition, the black chrome coating also has good weather resistance and corrosion resistance.
