BY THOMAS EBERT AND FRANK FRIEBEL
UMICORE GALVANOTECHNIK GMBH,
SCHWAEBISCH GMUEND, GERMANY
Platinized anodes optimize
dimensioning and construction
for hard chrome plating.
Titanium vs. Lead Anodes
in Hard Chrome Plating
ABOVE: Umicore Electroplating in Germany plates
anodes using high-temperature electrolysis. In this
process, platinum is deposited onto base materials
such as titanium, niobium, tantalum, molyb-
denum, tungsten, stainless steels and nickel
alloys in an argon atmosphere in a molten salt
bath at 550°C.
14
MARCH 2017 — PFonline.com
Lead is under a watchful eye across the globe. In the U.S.,
health and workplace authorities are insistent in their
warnings. Even if electroplating companies have decades of
experience working with hazardous substances, the metal is
still being seen in an increasingly critical light.
For example, anyone using lead anodes in the U.S. must
register with the federal EPA's Toxic Chemical Release Inventory.
If an electroplating company processes only around 29 kg of lead
in a year, registration is still required.
So, it is not only hard chrome platers that need to seek alterna-
tives in the U.S. Lead anodes may seem cheap at first glance but
also have a wide spectrum of disadvantages:
• They can deform (see Figure 1). The isolated metal, therefore,
cannot be equally distributed on the component. The layer
thickness varies: Too much chrome is applied to some areas
(waste of resources) and must be mechanically removed later.
• Maintenance costs are high. Repeated manual turning of the
heavy lead anodes is common. This prevents, for example, short
circuits via contact between anode and cathode.
• PbCrO
4
also builds up on the anode. If the power supply is inter-
rupted, lead chromate sludge can build up on the anode, and it
PLATING