Umicore hard gold electrolytes for optimized layer thickness distribution
Umicore Metal Deposition Solutions is responding to the rising gold price with the Auruna 526 and 527 hard gold electrolytes, which offer economic advantages thanks to their high process stability, good depth scattering and uniform layer thicknesses.
The sharp rise in the price of gold is bringing material-efficient coating processes into focus. Umicore MDS has developed the weakly acidic gold-cobalt electrolyte Auruna 526 and the gold-nickel electrolyte Auruna 527, hard gold electrolytes especially for small part mass plating in barrel plating and vibratory plating systems. With these electrolytes, a uniformly distributed gold layer of the desired thickness can be deposited for individual components despite the changing current density conditions typical of these plating methods. Particularly in the case of complex geometries, such as those found in plug contacts or contact sockets, conventional solutions often have difficulty depositing gold evenly in exposed areas and in recesses or cavities. A very uniform layer distribution makes it possible to achieve the minimum layer thickness at defined measuring points without unnecessary use of gold - even in geometrically complex components such as pin, spring and plug contacts as well as contact sockets and sleeves.
Auruna electrolytes for a balanced layer thickness ratio
The two Auruna hard gold electrolytes ensure a balanced layer thickness ratio and therefore a uniform minimum layer thickness at all relevant measuring points. This is due to the increased deposition rate at low current densities and the significantly reduced deposition rate at high current densities. This significantly reduces the overcoating typical of standard electrolytes and the associated unnecessary gold consumption - an advantage that is particularly noticeable with internal measuring points of sleeves or bushings. A comparison with a standard electrolyte shows a higher deposition rate at low current densities and a significantly lower reaction to high current densities. This results in more uniform layers in the bulk material barrel/vibration coating application area - overcoating and the so-called dog-bone effect are significantly reduced.
Hard gold electrolytes for cost optimization
As you would expect from high-quality hard gold electrolytes, the layers deposited from them are abrasion-resistant and meet the highest requirements for corrosion protection and low contact resistance for reliable contact applications. The contact transition resistance in internal test series is 3.33 mOhm for Auruna 526 and 3.26 mOhm for Auruna 527 (at 50 cN), which is within the characteristic range for hard gold coatings. The coated components can therefore also be used in demanding areas such as defense technology, as they comply with ASTM standard B 488-01, Type I, Code C. This is due to a high fineness of ~99.8 % and a hardness of ~150 HV, which ensure reliable functionality and durability. "With our Auruna processes, interested parties find an easy way to optimize their cost structure and thus remain competitive in these difficult economic times," says Benjamin Wieser, Division Manager for Technical Precious Metals at Umicore MDS, explaining the significant increase in demand for these hard gold electrolytes.