Black Chromium plating for Solar Enegry Application (Water Heater)

is a improved formula, specially designed for plating on the base metals of pure aluminum/ aluminum alloys/ copper/ steel etc. with uniform black chromium layer and thickness，moreover, the plated black chromium layer can conform to the standard requirements:  Absorption Rate-0.97, Refraction Rate-0.12, And the plating solution can show its stability in mass production.