TiN hard-coating punch 2

[IFRs]

Is there any benefit to coating punches with TiN? I've seen it on drill bits. A rep suggested it as a method to increase the life of our tooling. We punch 0.050" wide by 1.25" slots in 0.050" thick SS304. The punches don't last very long and cost a bundle to replace because they are a custom shape.

Anu information or help would be welcome !!

Thanks in advance !!

 

[unclesyd]

i was starting to post saying that it would be worth a try due to inprovement in wear on the side of the punch when i remember this article. Finally found it again.

http://www.sheetmetal2000.com/punching_tools.htm

 

[IFRs]

Thanks. The article reinforces what I had been told by a Danly rep. I'm going to give it a try.

 

[TVP]

There are a number of coating/heat treatment options available for improving punch life. Check out the following articles from Metalforming Magazine:

http://archive.metalformingmagazine.com/1999/03/tooling/PVDCVD/PVDCVD.htm

http://archive.metalformingmagazine.com/2003/07/NewCrN.pdf

http://archive.metalformingmagazine.com/1998/06/ARVIN/SUBSTRAT.htm

http://archive.metalformingmagazine.com/1998/06/DLC/dlc.htm

 

[richardbuss]

The main problem my clients have when punching punching stainless steel is adhesive wear. The TIN coating we do usually has a hardness of about 2500 HV which is a good start. For punching stainless steel including martensitic steels we take a tough tool steel material with about 54 - 56 HRc Hardness, plasma nitride it to give the coating a hard under layer and then coat with TICN. This has about 3000 HV hardness and has given us the best results.

Regards
Richard Buss

 

[NickE]

We use carbide punches and TiN coatings to stamp 54-56 HRc thin strip.

Im sure you wont loose any life by coating.

nick

 

[jmillard]

We use TiN coating on many of our punches. Using this coating has given the company two major benefits. First, it improves tool life be reducing wear to the punch. Second, the coating help prevent material buildup on the punch after extended use. We have had great sucess with both the TiN coating and and polished carbide. The price between the two has been comparible. In many cases carbide has is slightly more wear resistant, but is more likely to fail due to breakage. The TiN coating over a more ductile material will improve life and eliminate the breakage.

 

[cocobolorose]

This subject seems relevant to our problem where we are using cemented carbide wheels to score glass tubing in high speed production. Would a TiN-coated material be better, since we are losing a lot of carbide wheels due to chip-out on the cutting edges?

 

[NickE]

I think that the chip out you are experiencing is more due to impact forces and not so much Adhesion/wear. My simple mind says to try a higher binder carbide grade. I 'm not very familar with the application. Whats your supplier say?

nick

 

[mnielsen]

TiN coating is usually a good place to start. However, the coating industry (which I am a part of) has come a long way since the invention of TiN. Typically the wear seen on a punch of this nature would be adhesive wear on the shank of the punch and not from breaking down or rolling over the cutting edge. Working with Stainless makes wear mode even more likely. For this wear a trademark named coating called MoST is very effective. TiCN would by my second choice and TiN would be a distant third. Any of these can be obtained straight from your Danly rep, or the second two services can be purchased from almost any PVD coating supplier.

coco...I would agree that a coating would most likely not help a chipping problem. Finer grain or higher cobalt content would be the way to go.