Ruthenium BLACK 500

Ruthenium-BLACK-500
A high-quality ruthenium electrolyte for decorative black coatings. It is recommended to pre-coat parts with gold before rinsing and immersion into the Ruthenium-BLACK-500 bath. Substrates such as zinc, tin, lead, iron, and special bronze must first be coated with a sufficiently thick and dense layer of copper or nickel before applying ruthenium.

Coating 

• The black coatings are very hard (~800 HV), maintain their brightness, and show high corrosion resistance.
• The intensity of the black color can be easily controlled by varying the concentration of the Ruthenium-BLACK-500-B blackening additive
  

Equipment

• Recommended tanks: polypropylene (PP) or polyethylene (PE) with ventilation.
• Filtration: filtration pump for continuous electrolyte movement, filtration via polypropylene cartridge filters.
• Heating: porcelain or glass heating elements with thermostat control for 60–75 °C.
• Rectifier: continuous adjustment recommended.
• Anodes: platinized titanium mesh (anode/cathode surface ratio 2:1).
• Bath movement and recommended cathode movement.

Bath Preparation and Maintenance

• The plating tank is cleaned thoroughly, filled half with deionized water, then the ruthenium concentrate (25 g Ru/l) is added under stirring, filled to final volume with deionized water, and heated to 60 °C.
• Ruthenium content is maintained by addition of concentrate containing 25 g/l Ru plus other deposition-supporting components.

Safety and Disposal

• Contains free acid; classified as irritant. Material safety data sheet must be consulted before use.
• Contains substances highly hazardous to water; avoid discharge untreated into sewage or natural waters.
• Used electrolytes and precious metal-containing rinse solutions should be processed at recovery plants.
• Ruthenium-free solutions must be detoxified according to local wastewater regulations.

Blackening Additive (Ruthenium-BLACK-500-B)

• Controls the blackening degree of Ruthenium-BLACK-500.
• Dosage: 2–6 ml per gram Ru, depending on desired color intensity.
• During operation, continuous addition of about 4 ml per gram Ru is recommended to maintain blackness.
• The blackening dye slowly decomposes at the working temperature (60 °C), especially during breaks; intensity must be adjusted by renewing additive before further processing.