Electro-polishing stainless steel
Electro-polishing stainless steel
(OP)
Hi,
I need to know how much material is removed from stainless steel with electro-polishing. I have some laser drilled holes that are 10 microns (10 millionths of a metre) in diameter and i want to know how much the diameter will increase if they are electro-polished? And how much rounder will the holes get?
Regards,
Antknee.
I need to know how much material is removed from stainless steel with electro-polishing. I have some laser drilled holes that are 10 microns (10 millionths of a metre) in diameter and i want to know how much the diameter will increase if they are electro-polished? And how much rounder will the holes get?
Regards,
Antknee.
RE: Electro-polishing stainless steel
Here is a link to somebody with a bit more job knowlege.
B.E.
http://www.neelectropolishing.com/passivation.php
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
Does anyone know of a company that can electro-polish specialist parts for research and development? I've attached the job I need doing, it's very specialist.
Regards,
Antknee.
RE: Electro-polishing stainless steel
You must make electrical contact with the part. For this one you might need a contact spring on the back and then seal the edges with wax.
There will also be a working electrode. It will be similar shape to your part.
I don't know of any way to control the EP of half of the edge.
How has the part been prepared? this is the other half of the question on what surface finish do you need?
Contrary to popular perception EP only improves the micro surface finish, not the macro.
The mechanical polish prior to EP is critical to getting a consistent finish.
When we EP we aim to remove about 0.0005" of metal.
Is your hole through the disc? If so and you EP from one side the hole will become tapered.
In order to keep the hole straight and uniform you would need to have an electrode strung through it.
At this size I don't see that happening.
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Plymouth Tube
RE: Electro-polishing stainless steel
Hi Ed, yes I need to EP one face of the disc. The drilled holes are completly through the part, all 0.2mm, and the intention of the procedure is to shape the hole, giving the top half a bigger diameter. The surface finish isn't a consideration.
There is a way of doing this, but I'm not sure which companies could do it, or the exact mechanics. It is for R&D so I need just a couple of small parts at a time, and not rack upon rack. Does anyone who can do this spring to mind?
Removing 0.0005" (12 microns) will be too much so I presume I'd just get these EP for a short time?
Thanks,
Antknee.
RE: Electro-polishing stainless steel
You could try this on the bench top.
A glass battery box, some Cu plate and leads, a DC power supply, and EP solution (sulfuric/phosphoric with some additives).
It will take you longer to mount each part then EP it. This is a few minutes each is all.
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Plymouth Tube
RE: Electro-polishing stainless steel
Regards,
Antknee.
RE: Electro-polishing stainless steel
Buy the EP solution premixed from a supplier.
Info is out there on current density and such.
I won't try to remember, and risk telling you wrong.
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Plymouth Tube
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
I have had good results electropolishing stainless steel with just Dilute Phosphoric acid.
Since you are in the UK. I do not know what health and safety would have to say about that.
Are you still working in a test lab situation, or do you have your product into a manufacturing stage yet?
Berkshire.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Electro-polishing stainless steel
There are standard commercial sources for it pre-mixed, with additives in it.
You don't want to just use straight acid.
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Plymouth Tube
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
https://www.google.com/
stainless+electropolishing+solution+UK
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Plymouth Tube
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
You can buy sulfuric acid at Lowe's - here in the states. - a big box hardware store. Used to clean driveways, etc...
RE: Electro-polishing stainless steel
Try asking these people for a sample.
B.E.
http://www.kiloltd.co.uk/item/phosphoric-acid
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Electro-polishing stainless steel
Regards,
Ant.
RE: Electro-polishing stainless steel
http://www.surfinetek.com/electropolishing/electro...
Thanks,
Ant.
RE: Electro-polishing stainless steel
Please re-read Ed from Plymouth tubes posts to you, he has already covered that.
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Electro-polishing stainless steel
Yes there was a fair bit of info here that I read and passed over.
A spring and wax is a good way of connecting the part/anode. Cathode has to be at least as big as the part/anode.
I've done a bit of reading myself and a stainless steel cathode should be fine. I guess I'd better start looking for a glass box of some kind and get on with it.
Regards,
Ant.
RE: Electro-polishing stainless steel
RE: Electro-polishing stainless steel
We always use Cu for the cathode to minimize the voltage drop, at your low power SS should work fine.
It really should be about the same size(just a bit larger) than your work piece. You will need to keep them very parallel. Otherwise you will remove more metal where they are closer. Maybe use three small plastic beads glued to the cathode so that your work piece can sit at a uniform height.
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Plymouth Tube
RE: Electro-polishing stainless steel
I'm now seeing why earlier in the thread you mentioned it would take longer to set the jig than do the polishing. I have to make a bath/jig that will allow me to polish half of the thickness of my part (0.1mm) and be kept firmly in place and allow the cathode to be close and parallel to the part. This would be easier if I didn't have to get half of the part out of the water - I can't even see 0.1mm. I'm currently sat with the part and prospective cathode thinking about using beads and springs. Thanks, Ant.
RE: Electro-polishing stainless steel