How to make groove on the surface of nonferrous metal 8

[mingki]

Hi, I am trying to make groove on the surface of nonferrous metal(currently, I am using nickel, monel, inconel).
It is not easy because the thickness of the metal I am using is just 0.027mm.
How can I make groove(depth: 0.0135mm) on the surface of nonferrous metal which has the thickness of 0.027mm.
I am desperate. Please help me.

 

[cloa]

How about laser engraving. Why not contact a laser engraver in your area to see if they could do it.

 

[TVP]

I agree with cloa, some type of laser-based process would be at the top of my list. Google "laser engraving" for a description of the process, etc.

 

[mingki]

oh.. thank you very much for your ideas.
I forgot to mention one thing.
I shouldn't make the mechanical characteristics(such as tensile strength, elongation, hardness etc.) of the nonferrous metal changed by applying high heat on the material.
The mechanical characteristics should stay as its origianl state.
That's why I was thinking of machining the surface but how can I achieve engraving on such thickness?
Please advise me...

 

[unclesyd]

I would look at diamond tooling and wire.

I would give J&M a call and discuss your requirements. You may have to use a removable backup in the tube if machining. The use of diamond wire to cut a groove puts very little bending pressure on the pipe. You will have to build jig to hold the diamond wire. You have to anchor one end and have weight as tension device on the other end.

Do Not try to hold the wire by hand while using.

http://www.diamondtool.com/

http://www.mtixtl.com/search.aspx?find=diamond+wire

 

[MintJulep]

Possibly photoengraving.

 

[btrueblood]

Chemical (acid) etching, properly done, will give you a groove of any desired depth, controlled to within .0001" or less. Mint's answer is the same process, but done with a photo mask; other masking techniques including hand-layed masking is possible.

 

[EdStainless]

I like the chemical etch idea.
If you can mount the material so that it is well supported you could scribe a line that deep with a single point diamond tool, just like scribing a diffraction grating.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[mingki]

Thank you so much. Then, could you advise me how could I apply chemical etching method? I tried to find some tutorial on the web but I couldn't find one. What's the mechanism of this method? I hope I could make groove which has depth of 0.0135mm and 0.001~0.01mm wide and length of 1m without compromising the mechanical characteristics of the nonferrous metal I use.
High precision is also required.
Please help me...

 

[Compositepro]

Make a simple grooving tool with a tungsten carbide point that protrudes from a flat surface, like a plane. Use a straight edge to guide it and score the line by hand. Your groove is not much more than a scratch.

 

[btrueblood]

Re chem etching: I would suggest searching for a vendor who has experience in the process and contracting them to do the work for you. Thomas Register might be a good place to start, if you are in the US or can send the work there.

Barring that, you face a process of experimentation - get material samples, select candidate etching solutions (consulting a metallurgy/metallography text may be useful here), apply solutions (of varying strengths) to samples (for varying durations), apply a suitable alkali (one that won't evolve dangerous gases would be preferred) to neutralize remaining acid and stop the etching at the end of the specified durations, rinse, inspect, document, repeat. Oh, and I forgot to add, find candidate masking materials and application methods. Mint is right, that at your groove size you will probably need to use a photo process for the mask.

 

[TVP]

Here is one company that works in this area, with a technical description of the process:

http://www.photofabrication.com/etching-process/

 

[mingki]

Thank you so much for such valuable advise.
Unfortunately, contracting with specialized chem etching company is difficult for my current situation.
I am hoping that I could control the groove depth and the width, length precisely on the nonferrous metal by doing the process by myself. How can i evenly and precisely control them? I need to make(control) groove depth 0.0135mm~2mm, width up to 0.001mm~2mm.
I've thought of milling but the thickness of my materials are so thin(0.027mm~1mm) and they are all nonferrous metals, making it difficult for the materials to be cutted off. I even thought of scratching off the surface of nonferrous metal by doing the repeted scratching(X to Y, Y to X) motion with gradual height nerrowing of Z axis using CNC milling but I think this method compromises the precision of the measurement of groove depth,width,length. I already tried pressing using 150ton press. But, if I do this, the depth of groove is uneven and I have no idea how the mechanical materials charecteristics have been changed.....

 

[unclesyd]

As you mentioned A CNC machine a light went on, you may be able to use Drag Engraving to get your groove. Drag engraving used a non-rotating diamond point that uses the CNC for direction. In your case you would have to support the thin tube to be able to hold it without it moving and use the machine to move the tube. You might also be able to use a knee mill where you would use the spindle to hold the tool and the carriage to traverse the tube. If you go to J&M diamond tool company they make various type of points for drag engraving.

http://www.diamondtool.com/

http://www.widgetworksunlimited.com/CNC_Diamond_Drag_Engraving_Bit_p/cnc-dmnd_engrv.htm

 

[mingki]

Thank you so much. I will try that.
I just tried grinding on SUS316L(0.027mm thickness) by using a sharp tip grinder(?) to make groove. Unfortunately, the grinding job didn't remove the material, instead, it just squashed the material. I have a microscope, so I saw it by using it. The groove pattern is terribly uneven and it was almost like the result I get when I pressed the material with pressing machine. I think it is because of the elongation of SUS316L. I think they are very difficult to be drilled or cut off when the thickness is thin.
Drag engraving using a non-rotating diamond point and chemical etching would be the best option. Am I approching it right? I hope I could try the chemical etching method by myself. Is there any DIY method of doing it? How can I control the depth, width of the groove if I use chemical etching method? Please help me.

 

[unclesyd]

Just a thought, it is going to be difficult to keep your depth and width due to the fact that your are well within the outer limits of the specifications for your tube in chamber, straightness, etc. So I believe the spring loaded approach is mandatory. Ideally it would be better to draw the tube through a mandrel with the tool mounted in the ring. This would get rid of the dimensional tolerances of the tube.

Here are two links that maybe of some help. The first has a good selection of points in Carbide. The second is a company that makes electro-marking equipment that might be adapted for marking /etching linear parts.

http://www.2linc.com/engraving_tools_pro_micro.htm

http://www.img-electromark.com/

 

[mingki]

THanks a lot, unclesyd.
Actually, I am working on plates not tubes but I think they are applicable. Could you advise me what is the best way to cut nonferrous metal without affecting their mechanical characteristics?

 

[unclesyd]

Sorry about picking up that you were working with a tube, must have been a senior moment. It must be the first one as I can't remember any others.

Depending on the amount needed I would look into Electrochemical Milling as mentioned above.
Depend on the precision needed you can use a photo-mask or an insulating varnish like Glyptol. I used the red for a phosphoric acid electrolyte working with SS.

Here is a table of electrolytes from the link posted above.

http://www.img-electromark.com/table/

 

[mingki]

Thank you very much. Are there any tutorial for electrochemical milling? I have a tight budget and I can't afford to get help from companies. I must find a way to do it myself.
My goal is to make bursting disc using nonferrous metals. Since they are discs used to be ruptured when it reached to a certain pressure level, controlling that certain bursting pressure level is so difficult to achieve. That's why I need the mechanical characteristics of those nonferrous metals unchanged so that I can prepare a dozens of bursting discs in the same bursting pressure and the same specification. I am so excited doing this for myself. I hope I could have your continuos support then I will back to you with actual result. Please help me.

 

[HDS]

This is starting to sound like a university project.

When you say this is a bursting disc it sets of red flags and alarm bells about safety issues. Bursting discs are usually used in pressure vessels. Have you exhausted all the options in looking for commercially available bursting disc or relief valve?

If this is truly your only option you have to accept that you will have tolerances and the parts will not be perfect. You need to make the calculations for what those tolerances can be. Every process will change the material properties in someway.