The authoritative public forum
  for Metal Finishing since 1989
-----

Palladium-Cobalt Characteristics and Plating Problems

Q. Palladium Cobalt (PCP) is used in our plating shop to substitute for Palladium Nickel(PNP) for nickel-free products. Anyone could advise me some characteristics of PCP plating solution such as :
(1) What is the effect of temperature, pH, Be on the composition of Pd & Co;
(2) As stated in manual of the supplier, PCP layer normally contains 80-90% of Pd; In practice, close to/more than 90% Pd is plated in the layer (checked by x-ray); any good suggestion to keep the Pd content lower?

Deville Yiu
Sun Lick, - Hong Kong, China
2000

---

---

Keep Karat of Palladium Cobalt Plating Stable?

2000

Q. Palladium Cobalt (PdCo) is used instead of Palladium Nickel for Nickel-Free product. Due to the costing, it is preferred to use as low Pd content as possible (e.g., 80% Pd/20%Co.)

When a new PdCo bath is used, a 80%Pd/20%Co karat layer could be kept in normal plating operation. However, when the bath is used for several months, the karat of Pd/Co gets higher and higher and the replenishment of Pd gets higher to keep the bath content. As some supplier explained to me, even the cobalt content checked by AA is kept at certain level, the Co(II ion), which can easily deposit with Pd, in the bath changes to Co(III ion), which could not deposit with Pd, after the bath is used for a while.

Is it true?

If yes, is it possible to convert the Co(III ion) to Co(II ion) in the bath? Or how to keep the karat of Pd/Co plating as low as possible?

Deville Yiu [returning]
Sun Lick, Hong Kong, China - Hong Kong, China

---

---

Palladium cobalt alloy magnetic properties

Q. I am looking for specific data on the magnetic properties of palladium cobalt alloys. The best that I have been able to find is that they may be slightly magnetic. I need some specific hard data. I have a low level magnetic requirement. Can you help?

Thank you.

Frank Majeske
Boeing EDD - Torrance, California
2001

---

---

Palladium-Cobalt Adhesion Problem

2007

Q. Dear Sir/Madam,

I am having an adhesion problem with my electrolytic Palladium/Cobalt Alloy deposits on Electrolytic Nickel plated on Copper. First I plate Electrolytic Nickel on Copper, then plate Electrolytic Palladium/Cobalt on the Nickel. The Alloy composition should be 80% Palladium and 20% Cobalt.

The substrates are cleaned in 20% Sulfuric Acid before electrodeposition. I do not think my adhesion problem is caused by poor surface preparation. I think the problem is due to stress in the deposits either because of incorrect alloy composition or a deficiency in the stress reducing agent. The Cobalt concentration is controlled by a chelating agent, the concentration of which is unknown.

The thickness of the deposits is 2.0 microns run at a current density of 16.0 Amps/square foot.

What are your suggestions to improve the adhesion problem.

Thanks,

Maurice Mason
Plating Engineer - Danbury, Connecticut, USA

---

Q. HI TED,

THANKS FOR REPLYING. THE PALLADIUM/COBALT COMES OFF THE NICKEL. THE NICKEL REMAINS ON THE COPPER.

MAURICE

MAURICE MASON [returning]
- DANBURY, Connecticut, USA
2007

---

Q. Hi Ted,

Thanks again. I rinse the parts for approximately two minutes after Nickel Plating before they go in the Palladium/Cobalt bath. This is mainly to prevent contamination of the Palladium/Cobalt bath with any "drag out" from the Nickel bath. I try not to expose the parts to air. Am I rinsing too long?

Maurice Mason [returning]
- Danbury, Connecticut, USA
2007

---

! Hi Ted,

A chemical analysis of the Palladium/Cobalt Plating solution showed that a component used as a stress reducer was way below the recommended level. I added this component to the plating solution, allowed it to mix for about two hours, and the adhesion problem went away. Repeated tests since have still showed no adhesion problems.

Maurice Mason [returning]
- Danbury, Connecticut, USA
2007

---

---

Q. Hello. I am having similar problems but, in my case it is palladium nickel. I am plating 30 micro inches to a formed part and we are seeing some lifting on the edge of the part. Tried Wood's Nickel with low current but, the problem continues. How high should the current be in the Woods Nickel?

marco salazar
plating - waterbury Connecticut
October 8, 2018

---

Q Could anyone text me a supplier of PdCo plating solution?

Andy Liu
Suzhou MT - Suzhou, China
January 3, 2020

Ed. note: Sorry, this RFQ is old & outdated, so contact info is no longer available. However, if you feel that something technical should be said in reply, please post it; no public commercial suggestions please ( huh? why?)