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View Full Version : How to implant diamond dust in a steel plate or a wheel



Martin0001
10-10-2013, 02:51 PM
I have few nice diamond covered files and laps (and they are not cheap) and recently my friend have gave me some crystalline diamond, approximate grit is 60 and 100, got about an ounce of each and because my wife have shown no interest (she would like to have all of that in 1 chunk:) ) I am planning to do something useful with it.
For example it would be a good idea to embed it on a metal disc which later could be installed on a grinder, for a good tool grinder.
Commercial items like that can be expensive.

So how they are doing that in industry?
Best if no resins are involved as this sounds like a waste of diamond.
Any electroplating method which would bind initially mechanically embedded crystals with a layer of nickel or something alike?

Carm
10-10-2013, 04:25 PM
You can roll the bort into the disc using olive oil as a lube. The roller is a ball bearing mounted on a shank to hold onto. Copper makes a good disc, alooneyum will work.
Sprinkle a little bort into the olive oil and embed with pressure. A slow rev knee mill or drill press works. Lathe too, but capture the falling diamonds.

Jaakko Fagerlund
10-10-2013, 04:25 PM
At least on lapping plates yu can embed it with a bearing, as it pushes the diamonds inside the material. But, this might not be a "right way" to do it, I just remember reading from this idea somewhere some time ago, in a galaxy far far away...

Forrest Addy
10-10-2013, 04:58 PM
60 to 100 grit? Typically large grits like this are plated on the substrate.

I'm guessing here but I think the process goes like this: scatter the grit over the cleaned plate and, being careful not to disturb the diamonds, submerge the surface in electroless nickel solution until enough nickel builds uo to capture them.

60 grit is REALLY coarse. Can you possibly trade if for 150 or finer? Diiamond is several time nore agressive than aluminum oxide of the same grit size.

Martin0001
10-10-2013, 05:54 PM
I don't think, I can exchange these diamonds for some finer grit.
Diamonds, even if very hard, can be easily powderized in steel or agate mortar and then steel dust contaminating diamonds removed by treatment with hydrochloric acid or agate powder powder removed by treatment with hydrofluoric acid (the latter is quite nasty btw).
However before any experiments like that I would like to make sure that I can actually bind diamond with substrate plate.
Nickel plating, electroless or otherwise seems to be a process employed because surfaces of diamond laps look like nickel plated and also on one lap which I got from company called DMT there is a clear warning that
"product contain nickel, known to the state of California to be blah blah blah"

Any trade names or names of suppliers of commercial solutions allowing electroless nickel plating?
From what I know these solutions often contain chemicals like hypophosphites or borohydrides, tedious to acquire.

Stern
10-10-2013, 06:25 PM
Yea, Caswell makes an electroless plating system for nickel (as well as tin, copper and a super hard coating called Krome, which is nickel based and 4 times harder than chrome). Use is simple, buy the kit, use the heater (like a fish tank heater) to warm the solution, drop the part in and leave it XX min for every YY micron layer you want.

Martin0001
10-10-2013, 08:33 PM
Thanks for that info, Stern.
Should be much simpler than acquiring separate chemicals and trying to replicate results which are often patented and even in research publications disclosed without detailed experimental section.

Forrest Addy
10-11-2013, 06:23 AM
BTW, I should have mentioned: tool grinder? For steel tools? Diamond does not hold up grinding steel. Counter-intuitive but true with soft steel being worse than hard.

While diamond is by far the hardest substance, a diamond grinding wheel used on iron or steel wears rapidly. I suspect because carbon is soluable in iron. I think it works this way: the flash temperature of grinding causes the diamond to fuse with the iron and since iron carbide is weaker than diamond it instantly transfers mostly to the swarf and maybe to the work.

If you wish to grind steel tools you better use wheels having CBN abrasive (even more expensive than industrial diamond).

Jaakko Fagerlund
10-11-2013, 09:42 AM
Forrest, this has been gone over many times but diamond is fine for grinding HSS tools and last very long, as long as one doesn't "have at it" in a few seconds, but goes gently.

And diamond dissolves in iron, just as when heat treating (carbonising), but not readily, requires high heat. And yes, as I discussed this in a previous thread of mine, it doesn't act instantly or even in long run. I tried getting diamond to dissolve in S355 bar from a diamond grinding wheel, but all I got was tes of millimeters shorter bar. And I really tried to push it to the high heat and all I could until I had practically no bar left. The diamond coating? Didn't show a sign of wear.

Duffy
10-12-2013, 11:48 AM
The idea of nickel plating to trap the diamonds, using a home-built plating system is strictly that:- an idea. Consider the actual problems and it will not be worth the effort. First, the steel plate has to be acid cleaned and flashed with copper, then the grit has to be uniformly distributed over the flat plate. Then it must be held in place somehow, preferably so that the plate can be immersed vertically into a fairly hot, alkaline cyanide plating bath. That means forget any obvious adhesive choices, as they will break down. Also, the steel has to be exposed to the bath to be conductive. The plating has to continue until the nickel layer has built up to slightly over 1/2 the height of the grit grains to ensure that they are really trapped. That will take quite a while. Usually plating thickness is measured in tenths, but in the case of 100 grit you are dealling in several thousandths; 60 grit would be even worse. To maintain the plates horizontal in the bath, which would overcome the adhesion process, you will have to figure out a practical way of mounting the nickel plate close to, (for throwing power,) and above the steel plate. This of course leaves you blind to the progress, and may introduce problems of electrolyte concentration gradients.
You might be farther ahead to try bonding the grit to brass plate using a hard, (high antimony,) solder. Tin the plate fairly heavily, distribute the grit evenly and roll or press it into the tinning, put plate on an electric hot plate and when the tin coat melts, carefully melt in more solder, until the grit is about half submerged.
Someone will say this is plain nuts, but I believe that it has at least a chance of success.