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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Plating Nickel onto Titanium
Q. I need technical information on electroplating pure gold and palladium onto pure titanium. I understand that you have to clean titanium and you have to protect the surface from oxidizing again before electroplating. can any one help with a proposed cleaning process and plating cycles. Thank you
ROY CONIGLIONE1995
A. Hi, Roy. Indeed titanium is very difficult to plate onto because of the tenacious oxide film it forms very quickly. ASM International's "Metals Handbook--Volume 5: Surface Engineering has an outstanding chapter on how to plate onto titanium and other hard to plate metals. But it always involves very aggressive acids, followed by care in quickly get a coating of another metal onto it.
Nickel plating is usually a vital part of the sequence.
In addition, one method/enhancement I know of is to nickel plate the object and then heat it to diffuse the nickel into the titanium. Letter
13456 offers some details on that. Good luck with it.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. I would suggest looking into Aurobond TCL Gold Strike (Sel-Rex) for the initial strike for Ti. It has always been superior to Wood's Ni strike for difficult SS plating problems. Sel Rex does recommend it for Ti.
Kirk McGlothlanA. We once plated gold onto Ti wire, we used an existing process we have for plating onto Mo wire
Which is …
Anneal the wire at 900C at 15 meters/min under H2
0.5 -1.0 micron Flash in Ni Sulphamate … (There is no real need for electrolytic cleaning as this promotes oxide on the Ti)
A gold flash may also help, as when the material is re-annealed a Ni/Au alloy is formed.
Re-Anneal at 1100 °C at 15/M.Min to diffuse some Ni into the Ti
At this stage check for blistering, if there is still oxide on the Ti, the nickel will not diffuse..
Plate..
Hope this is of some use...
A. How are you you doing the nickel plating on titanium?
Method A: 1.Alkaline degreasing with 50 g/l NaOH 50 g/l NaCO3 2.Rinse 3.Etching in hydrochloric acid time 3 minutes 4.Rinse in Rochelle salt acid 5. Copper strike 50 g/l and 160 Rochelle salt acid in 5 minutes 0,4 A/dm 6. Rinse in sulfuric acid.
Method B: 1. Alkaline degreasing with 50g/l NaOH 50g/l NaOH3 2. Rinse 3. Wet blasting with aluminium oxide carefully over the part. 4. Activation 325-450 g/l hydrofluoric acid 3 minutes after gassing. 5. Neutralizing in 50g/l potassium tartrate 6. Copper strike See method 1: After one of these steps you can plate nickel or chromium.
Good Luck to all. Regard Anders. S
Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
1999
A. Electroplating Engineering Handbook [on
AbeBooks or
eBay or
Amazon affil links]
edited by L.Durney.
Titanium passivates very rapidly so there can be no delay between tanks.
I assume that you are on 6-4 Ti. Watch your caustic step as it can cause problems by etching out some of the aluminum.worm pitting.
I am in favor of a nickel strike, high acid low nickel and then directly into the nickel plate tank with minimal rinsing.
I wood skip the neutralizing step after the HF activation.
I would also activate in a 35-45% nitric and 4-5% HF. It works fine and is less critical. This chemically polishes as well as activates. If this is too slow, try it in the lab, gradually increasing both acids. 7 nitric to 1 HF is as low as you should go in the ratio, and 14 - 1 is the weakest HF ratio.
- Navarre, Florida
A. Hi Jim. We already use method number 1 without any problem. About method number 2 I can see that be wrong with using hydrofluoric acid but I mean hydrochloric acid. We have no problem with etching step. Obvious there exist more ways to do plating on Titanium. I'm going to buy that book you recommend from the book store. Thanks for your answer Jim.
Regards
Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
I ordered this. -thank you
- Miami, FL
October 22, 2022
Q. Hello!
I am looking into the improvement of my laboratory's ability to plate Ni on to Ti because of we are having problems meeting extremely rigorous adhesion criteria.
At this time our Ti substrate is grit blasted with Al2O3 media, ultrasonically cleaned with alkaline cleaner, etched with 35% HNO3 + 2% HF, and then given a standard Woods Ni strike. After that the parts are electroplated with a few more mils of Ni using a conventional Ni sulfamate bath, and then a final layer of electrodeposited Sn is added to the parts. We are seeing loss of adhesion between the Ti and the Ni.
I spoke with a couple of vendors yesterday (Atotech and Enthone OMI), and they made the following suggestions to improve the adhesion between the Ni and the Ti:
Atotech Vendor:
1) Instead of a standard Woods nickel strike, he suggested switching to a nickel bromide strike. He said that since nickel bromide attacks Ti in aqueous solution (quoted Ti basket vendor indications and literature), then it should activate the Ti surface to a greater extent than NiCl strike.
2) Increase the duration of the Ni strike. He said for us to analyze the region of poor adhesion on the Ti part and look for a pincushion effect. If there is a pincushion effect then it is likely from areas of the Ni strike that are not thick enough. This would allow any exposed areas of the Ti to become passivated, and could be easily avoided if we just make the Ni strike thicker.
Enthone OMI:
The vendor from Enthone OMI indicated that we cannot be entirely sure that our problem is between the Ti and the Ni because of how thin a Ni strike typically is. If any passivation occurs to the Ni strike before Ni sulfamate (i.e. while the parts are waiting in a beaker [beakers on
eBay
or
Amazon [affil links] of water) it could be enough to result in poor adhesion between those two layers. As a remedy to this problem he suggested that immediately prior to Ni sulfamate we perform an additional HNO3/HF etch for 10 seconds (or so) followed by a rinse step.
If anyone else has suggestions for my process of plating Ni on to Ti, please let me know.
Thanks,
Chris Adams
Lockheed Martin
2000
A. Hi, Chris. Getting adhesion onto titanium isn't easy, as you know. You might want to check Volume 5: Surface Engineering of ASMI's Metals Handbook which suggests immersion in much stronger nitric/hydrofluoric acid than you are using; followed by immersion in a hot and strong dichromate/HF mix; followed by acid copper plating. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. Chris,
Following up on Enthone/OMI's comment; I think in any bonding problem (plating or other) it's important to find to identify the true plane of failure, in this case Ni strike / Ti,or possibly sulfamate Ni / woods Ni. You may save yourself some time and money in the long run by having some elemental analysis run. Most SEMs are equipped with x-ray analysis and x-ray mapping capability. If this is not available in house you might try a local university, or a company that offers analytical services.
This is a fairly routine kind of analysis now.
- Putnam, Connecticut
A. I have plated nickel on titanium with adhesion values up to 35,000 psi (ring shear test). The process involves grit blasting the titanium, striking in a sulfamate bath and diffusion bonding in a vacuum oven at 1000 C. Works every time.
R.D. Mikkolaaerospace - Oak Ridge, Tennessee
Q. I am picking up on the letter from Christian Adams, in which he talks of a Nickel Bromide strike bath. Has anyone the breakdown on this bath, or info. on who sells it?
Thanks,
1998
A. I believe I used to analyze a nickel bromide bath. I don't remember the concentrations, but the solution looked about the consistency of lime juice, so what would that be, about 1 oz./gallon nickel metal? , I think the bromide will analyze using the usual nickel chloride titration and making the atomic weight adjustment., pH is about 2.0, I believe. Since the bath is thin, use a low current density, you are only using it for activation of the Ti, based on the above answers to the original question.
Tom Pullizzi
Falls Township, Pennsylvania
Correction! D. Gardner Foulke, in Electroplaters' Process Control Handbook ⇦[this on Amazon affil links], 1975, Robt. Krieger Publishing, Malabar, Florida, informs me that Bromide will interfere with that chloride analysis, so I guess I used to do the EDTA titration for nickel, and calculate from there.
Tom Pullizzi
Falls Township, Pennsylvania
Multiple threads merged: please forgive chronology errors and repetition 🙂
Q. Hello - I found your website on the internet.
We are having trouble with our current vendor who is plating nickel onto our hydraulic actuator cylinder bores.
The coatings have poor adhesion, blistering, pits in substrate, excessive mud-cracking ... etc.
Can you please send any information you have on plating titanium, or call me to discuss this process at your earliest convenience.
Best Regards,
-Irvine, California
2000
A. Hi Terence. This site has a huge amount of info on plating nickel onto titanium. Please see not only this thread but
Thread 40558, "Adhesion of plating on titanium" and
Thread 13456, "Blistering problems in Nickel Plating on Titanium"
and search the site for "Plate nickel on titanium".
Finishing.com does not offer private consulting -- we can only communicate publicly; but if you wish to retain a consultant please see our Directory of Consultants.
Luck & Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Hi terence,
I am no electro plater but I have some knowledge of titanium.I have a solution to your problem of Nickel plating on Ti-6Al4V.
You are unable to achieve Ni plating on Ti possibly due to process limitation in the presence of a tenacious oxide film which inhibits plating adherence. Here is a step by step procedure which will solve your problem
1)Scour with pumice powder and alkaline solution containing 50 g/l of Sodium hydroxide and 50 g/l sodium carbonate
⇦ this on
eBay or
Amazon]
2) rinse with water
3) Etch in hydrochloric acid solution containing .05 g/l choloroplatinic acid at 30 °C.Immersion time required varies with the alloy.Eg:2 Hours for IMI 314 and 10 minutes for IMI 680
4)Transfer the etched titanium to a solution containing 50 g/l Rochelle salt
⇦ this on
eBay
or
Amazon [affil links]
at room temperature. Gentle agitation is required.
5)Transfer rapidly to a copper tartrate plating solution containing 50 g/l copper sulphate
⇦ this on
eBay or
Amazon [affil links] ,160 g/l Rochelle salt ,50 g/l Sodium Hydroxide.Load live and plate for 5 minutes at 0.4 A-(dm square)
6)Rinse in water containing 1 v/o sulfuric acid
7)plate with nickel
8)Rinse and dry
9)Heat treat if necessary
Refer ASTM B481 "Recommended practice for preparation of titanium and titanium alloys for electro plating". I hope this will solve your problem.
With warm regards
hindustan aeronautics limited - Bangalore .Karnataka .india
Multiple threads merged: please forgive chronology errors and repetition 🙂
Q. Hi,
I'd like to have some help to discuss my suggestion for plating nickel on titanium Ti6Al4V.
1. Blasting with dry 120 grit aluminium oxide or with wet 500 grit aluminium sludge.
2. Rinse.
3. Electro cleaning for 1 minutes.
4. Rinse in citric water (It's to complex binder the TiO2.)
5. Etch in HNO3-HF for 1 minute. (It's for the Alpha phase)
6. Rinse in citric water.
7. Etch in HCl-NaF-NaCl for 1 minute. (It's for the Beta phase and also to activate the Vanadium which will be passivated in HNO3-HF.
8. Rinse in citric water.
9. Etch in Na2Cr2O7-HF for 5 minutes.(It's for the Alpha phase and also to clean the area from aluminium oxide from step No 7
10. Rinse in citric water.
11. Activation in Citric-HF for 1 minutes. The area should be light grey like a stainless steel surface at this step.
12. Rinse in citric water.
13. Nickel strike with a high CD for a few sec, and after that normal CD. (It's to get a Titanium hydride at the surface.
14. Nickel plate.
15. Bake at 480 °C.
All these pretreatment steps and plating are done in an argon air atmosphere. This pretreatment should give an adhesion about 150-300 Mpa. I hope people who enjoy this site here at finishing.com will discuss this operation so it could be better.
Best Regards,
Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
2002
? Have you attempted this yourself with success? I like the citric rinses; makes a lot of sense. j
Jon Quirt- Fridley, Minnesota
A. Jon,
Yes this pretreatment step work for me. The adhesion I have got is from 58-80 Mpa. Next step for me is to see if the adhesion will be better if the bake is 4 hour instead for 2 hour. The citric acid is to complex binding the titanium oxide.
Anders S
Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
A. Recently we have successfully done nickel plating on titanium alloys. First titanium was pickled with Nitric acid (69%) 3 volumes and HF (60%) one volume until red fumes just evolved. Then component etched with 240 g/l sodium dichromate and 40 ml/l of HF for 20 min at 80 degrees temperature. Then immediately carried out nickel plating with normal Watts bath. You will get excellent adhesive nickel plating.
B.V. Subba Rao- Hyderabad, Andhra Pradesh, India
May 2012
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