Formula for electroless nickel plating solution

A. Hi Brandon. All or most vendors substantially reformulated in just the last few years as lead and other non-RoHS stabilizers were removed. Still, probably nothing is more important than accurate temperature control because deposition rate is nearly asymptotic per Lowenheim's "Electroplating" ⇦[this on eBay , Amazon, AbeBooks affil links] and "Modern Electroplating" [on AbeBooks, eBay, or Amazon affil links] . And you must be careful not just to control it overall but to avoid hotspots. If you are able to get from 40 °C to 50 °C is less than say an hour, it's possible that local overheating is part of the problem.

Another thing to keep in mind when prototyping is that you may be tempted to use a tank which is too small for the surface area. Lowenheim says about 125 cm2/L is appropriate.

Luck & Regards,

"Electroplating"
by F.A. Lowenheim

on AbeBooks

or eBay or

Amazon

(affil links)

A. Hi Nico. Lowenheim's "Electroplating" offers over a dozen different formulations, and you'll probably find some additional formulas in other texts and literature from the 1950s, 1960s, and early 1970s, but electroless nickel formulas today are for all practical purposes proprietary. In other words, no user formulates them from basic compounds; they buy it from one of the many suppliers to the plating industry. That way you get a solution that works, you get full operating instructions (technical data sheet), you get analytical help, and you avoid mistakes like materials that are not RoHS-compliant .

You may already realize this, but plating jobshops are available which offer the service as well. Good luck.

A. Hi Maryam. Almost surely your university or other local technical library will have a copy of either Lowenheim's "Modern Electroplating" or his "Electroplating". Each has more than a dozen formulations you can experiment with, plus excellent discussions on the effects of different variables. Good luck.

Luck & Regards,

A. Obviously there are basic (generic) formulations for those baths they can be found in literature ASM handbook #5, Modern Electroplating by Schlesinger & Paunovic, and especially there is a book dedicated to that type of bath is on this site on the "must have" books list.

The best idea is to buy them not only for the authors dedication to develop these tasks, but also because it needs a wider understanding of the process equipment which is not covered having the formulation.

But if that is not possible please let me know and I will send you some formulations for them.

A. In this system you need nickel sulphate, sodium hypophosphite, and additives
For example :
100 lts bath make up, you need:
------------------------
3 kgs nickel sulphate
3.750 kgs sodium hypophosphite
6 kg additive

Is this enough from me?
regards

A. Mr/Mrs

Electroless nickel has several steps.

But before that:
What kind of substrate is the one you want to plate?

If it is plastic it needs an etching step which is done in a concentrated solution of chromic acid plus sulfuric acid

It works fine for ABS plastic but the other types of plastic I do not know; literature says PVC and others can be plated ok, but the best is ABS.

And then the surface must be rendered conductive.

If it is a conductor, well here are basic bath formulations --

acid baths using sodium hypophosphite
1)
nickel chloride 30 gr/litre
sodium hypophosphite 10 gr/litre
hydroxyacetic acid ⇦this on eBay or Amazon [affil links] 35 gr/litre
pH 4-6
temperature 100 °C
2)
nickel chloride 30 gr/litre
sodium hypophosphite 10gr/liter
sodium citrate 12.6 gr/liter
sodium acetate 5 gr/liter

pH 4-6
temperature 100 °C

There also are alkaline baths

Also you can find different reducing agents like sodium borohydride, and dimethylamine borane and hydrazine.

A. nickel sulphate 40 g/l
sodium hypophosphite 26 g/l
succinic acid 50 g/l
temp 85-95 °C

A. Hi Sunil. We appended your inquiry to this thread where some of the answers you seek are already available. Good luck.

But please provide us the background of who you are and what you are trying to do because otherwise the answers provided can be misleading. For example, in general, individuals don't formulate such solutions from raw chemicals, they buy them as proprietaries -- but we don't know if you already know that.

If you are a PhD student though, you may want to play with these solutions in the lab anyway as a matter of research. If you are a plating shop, most of us would consider it wasteful to make expensive solutions that will not yield enough turnovers because they do not contain the carefully developed proprietaries.

Silver based metallizing solutions based on the Brashear process and similar mixes of silver salts and reducing agents can perhaps be used for your application (you haven't told us what it is), but it may be a poor idea and it is not the most common route to metallizing materials for subsequent electroless nickel deposition. Best of luck.

Regards,

A. Hi Sunil. David Hernandez gives his formula for generic electroless nickel using those ingredients just above in his posting of Dec. 30, 2011. A good explanation of two-part silvering, and a discussion of how to sensitize the surface for it is in thread 23536. Good luck.

Luck & Regards,

A. Hi Mohammad,

The rule of thumb is to add everything first (reducing agent, pH buffer, stabilizer, etc.) prior to the nickel sulphate.

Regards,
David

"Modern Electroplating"
by F.A. Lowenheim

on AbeBooks

or eBay

or Amazon

(affil links)

A. Hi Maria. Although there are technologies that are "licensed" such that you buy the knowledge, and there are also consultants who can sell you the knowledge, in electroless nickel plating you generally "buy the process", i.e., the seller provides their products by the gallon, with the necessary instructions.

But if you still want to make your own solution, start with any of the formulations shown on this page, and ask detailed followup questions if necessary regarding the answers already offered. The substrate being 4140 steel probably doesn't affect the formulation. Alternately your university or city surely has books on the subject. Lowenheim's "Modern Electroplating, for example, offers 8 formulations for hypophosphite baths, plus 4 formulations for borohydride baths, and 6 for DMAB. Good luck.

As for how long the bath will work, understand that however much nickel you want to put on the parts had to come from the bath. So if you are doing a generic formula capable of only "one metal turn-over", the amount of nickel in the make-up tells you the maximum amount of nickel you could possibly plate out from it. But, in Lowenheim again, is the claim that not more than a g-atom of nickel can be generated for each mole of hydrogen released -- so it's quite limited. Have a good project!

Regards,

A. Hi Maria
Electroless nickel processes are not as simple as the published formulations suggest. You could waste a lot of time and money on chemicals and detract from your main project.
I would suggest that you approach the suppliers of established processes and explain your situation.
You will probably find them very helpful. Remember that today's poor student could be tomorrow's major buyer

A. I had the same experience, I sourced the sodium hypophosphite from abroad because it's very hard to get in the USA (it's a controlled substance used in the synthesis of illegal drugs) and I got the same result as you did; I gave up trying to make my own formula. The good news is that there are USA-based providers that sell the electroless nickel plating solutions separately (Solutions A, B and C), the solution A is just Nickel sulphate (20 grams per litter of Di water), the solution B is what have the hypophosphite and buffers, the solution C is a rejuvenator.

For a Proof of Concept I just got the solution B and got good results from it (nothing commercial grade of course).. Just search for Electroless Concentrate Part B and you will find it easy, I have tested the same solution with Nickel sulphate, Cobalt sulphate, Iron sulphate, and other metal sulphates mixed with nickel/cobalt and the results are very promising for many types of industries.

A few pics of the chemicals and solutions I've got:

        

A. ASTM B656 will give you formulas for Autocatalytic Ni-P deposition.

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Ed. notes: ASTM says that ASTM B656 referenced in Jim's posting is "inactive", but copies are available.