Cutting Thin Foil Shapes

You may be able to plate them onto a surface that has a patterned conductive area that is not strongly adherent. Then the problem is to remove them, possibly a solvent to degrade the adherence.

some experimentation would be needed, and the ability to plate the alloy would be critical. Most plating is pure metals

"fineblanking" process seems to be method evolved specifically to over come the issues faced by you. Google to get wealth of details.

We tried asking a fine blanking company but the said they could not hold a part this thin.

Hi,

which type of chemical etch did you try?

If patterned the material to prevent etch attack except where to cut then electrolytic etch will do a good job.

Any metal that is difficult to etch chemically - inert, noble or passivating - will easily be etched electrolytically.

The sludge to be reprocessed - either poisonous or valuable or both.

Start with any acid or caustic or salt (in diluted solution of pure water) that will not attack your material, take a variable low-voltage DC power supply (1 to 10 V and 1 to 4 A) will be good for a test), connect your parts (connection to be isolated as non-attacked regions) to the + voltage, surround by metal, graphite at - voltage with some cm distance and let the process go.

Acids will give a clear solution - often looked for in precision parts, else hydroxides will precipitate.

Avoid chlorides as these will require extra cleaning and maintenance to avoid corrosion on storage.

Sulfates or nitrates are a good choice, also sulfuric or nitric acid (at 10% you will need carefully protect your eyes and see much later only the holes in your clothing where you spilled the stuff).

RHABE

RHABE

This sounds promising, I've found a couple of companies that offer this process & will send them some drawings.

With wire EDM (Electric Discharge Machining), you can stack say 50 layers of foil and cut 50 at a time. You will need to hold the foils appropriately, as between sacrificial layers of thicker sheet, and you will have to drill or otherwise perforate a starting hole for each stack of washers. EDM is slow, but since you are cutting so many at once, it should be economical. No Dies to sharpen, no burrs, no garnet or other contamination...

We did talk to an EDM company about wire erosion, they seemed to have a problem with containing all of the parts once they had cut through. Maybe they were just being a bit negative.

Your EDM guy was very weak on imagination! Washers that size are going to take many minutes to cut, so there is plenty of time to insert a clamping device after the second (outer) cut is half done, with or without stopping the cut. 2mm between the clamp and the cut is plenty of clearance. We recently did a job using 6 sets of clamps, removing only one of the 6 at a time, and replacing each when the wire was past that clamp. There were always 5 clamps in place, which guaranteed that the part did not move during the process.

Again in your process, I'm assuming a sacrifical plate say 4mm thick on the top and bottom of the stack.

Punch and Die is the best method for material that thick......this would be dependant on the quantity of washers required.

When you say that the material is to difficult to hold how are you holding it?

2 flat plates is a method we have used in the past to perform such an operation with material at that thickness.

Your biggest challenge would be to getting the clearance between the punch and die correct as this clearance would be 5% of material thickness generally.

Nigh if you are unable to solve this one we are more than happy to put a design together or manufacture the foil shapes you need.

We can be contacted at www.alnoproductservices.com.au or info@alnoproductservices.com.au

We are in Australia but don't hold that against us.

Anthony

The clearances at 5% of material would be measured in microns.

The existing punch & die process uses conventional stripper plates.

We buy components & sell finished products all around the world but, although we deal with some Australian universities, I can't think of any parts that we buy from there. Maybe it's time we started.

I'll send you a couple of drawings.

I have a method for you but find that I cannot post an image, send an email and i will forward the idea.

Both Anthony & Telzar have offered solutions & I've enquired about the electrolytic etch so I'll hopefully be able to use one of these.