AURUNA® 311 For Technical Applications Gold Cobalt Electrolyte

For direct gold plating with good adhesion on stainless steel and nickel.

AURUNA® 311 for technical plating is a strongly acidic gold alloy electrolyte designed for direct gold plating with good adhesion on stainless steel. The solution is particularly suitable for chromium-nickel steel, molybdenum steel, and nickel-based alloys that are difficult to activate. Thanks to its strong activation capability, it can also be used effectively for many other passive materials that are difficult to plate.

This gold plating solution is suitable for both gold strike layers and thick technical gold deposits. The coating is ductile, low-porosity, and provides good corrosion resistance.

AURUNA® 311 for technical plating can be used for rack plating, barrel plating, and reel-to-reel plating, such as spray cell, dip cell, and brush plating.

Solution characteristics
Solution type: Strongly acidic
Metal content: 2 (1 – 10) g/L Au
pH value: 0.6 (0.1 – 0.8)
Operating temperature: 25 (20 – 40) °C
Current density range: 2 – 6 A/dm²
Plating rate: 0.08 μm/min at 2 g/L Au, 2 A/dm²
Anode material: Pt-Ti, MMO, PLATINODE® 177 type

Coating characteristics
Coating: Gold-cobalt
Alloy composition: approx. 99.7 wt.% Au; 0.3 wt.% Co
Deposit color: Deep gold
Brightness: Bright
Hardness: 160 HV
Maximum coating thickness: 10 μm

Advantages
Strongly acidic gold alloy electrolyte for direct gold plating on stainless steel and nickel
Very good activation efficiency, halogenide-free
Low-porosity, ductile, and crack-free coating
Suitable for both gold strike layers and thick deposits
Good deposit distribution
RoHS-compliant coating
Special cobalt-free version available
Suitable for rack plating, barrel plating, and reel-to-reel plating

Applications
Electrical contacts
Stainless steel contacts
Stainless steel springs