Need Help!- Drilling Inconel

[mmiranda]

Has anyone drilled small holes (.018-.030) in Inconel 625 at 10-12 diameters deep? Is it even possible?

[RICHARD ZASTROW]

EDM sinker with tubular electrode. Flush fluid thru electrode for thru holes. Solid electrode for blind holes.

Just possible solution.

Dick Z

[mmiranda]

Thank you Dick,
I am sure this will work. Part is very small and the costs I have received on this process are very expnesive. I was looking for someone that has tried to drill it. I have a customer that seems to know more than everyone else. I do appreciate your input and am gathering all similiar info to try to convience him.
Mike

[keebler303]

Bill O'Grady at Willmar Rotary Tool in Michigan has significant experience with small hole drilling. He also sells the tools so he can set you up with the drills you need if it sounds feasible. I'm not sure if its possible or not but he would be the guy to talk to. Contact info here:

http://www.iserv.net/~wmogrady/bassett.html#menu

Matt

[RICHARD ZASTROW]

Mike, Consider also, the possibility of work-hardening when drilling.

Dick Z

[Delw]

its very possible and can be done, we usually used a manual mill as teh cnc couldnt feel if a dril was loading up.

Its been a bunch of years but this is how we did it using 1/32 drills for deep stuff.

it takes about 3 drills per hole ( plan on it DONT push the drill any harder)
you will need a hardend drill bushing ITS A MUST with out it your drill will snap. so you will have to make a fixture to hold the drill bushing.
your start drill will go about .050-.100 before it dulls up
the break out drill don't use them again as they will break.
I used precision highspeed twist drill(Brand name) 159 degree split point the cobalt ones They are R18CO
If I remember correctly we ran 800 rpms, Make sure you peck alot as the chips will build up quick, use plenty of oil.
dont stop and talk to someone with the drill still spinning in the hole, Don't baby the drill when you start the cut, the drill bushing will keep the drill very stout so you can put pressure on it.
Make sure you only have about .1 of the drill above the drill bushing at any one time ,you will have to re chuck depending on how deep.

make your bushing tight to the face of the part other wise the tip will walk when you start the hole and your drill is no good.

we also did quite a few wire holes down to .015 on nickle alloys, you ahve to get a feel for it and the material will workharden.

I would seriously think of edm'ing them

[cdlenterprises]

I did a job like that a few years back. I think it was a 1/32 dia. drill. TiAlN coated COBALT drill- not HSS, not carbide. Cobalt has just enough toughness to handle some abuse and is just hard enough to give you manageable tool life. I would plan on at least one drill per hole as a MINIMUM. I think the sfm was in the 50 sfm range which gives you an rpm of around 6400 rpm (yes that's correct - 6400 rpm) All of the rules that you would use for cutting a nasty stainless (316, etc) apply here - Don't baby the feedrate or it'll workharden and if your going to spot it make sure it's the same drill point angle as the drill that your using. Inconel is definitely some tough stuff but it's machinable and manageable with the right tools and speeds.

[BYTHEBOOKBOB]

We drill Inconel 600, 625, X750 and 909 routinely down to .020 diameter and as much as 20x deep. We used Mitsubishi MINI-MWS carbide drills. Use their miracle star spot drills to spot and then get drilling feeds and speeds from their technical people. The feed and speeds for these drills is unbelievable. The coolant through drills are available down to 0.5 mm diameter and can drill up to 30x drill diameter. Don;t peck and use oil as well as high pressure if possible.

Good Luck,

Bythebookbob

[cnvenes]

I do know it can be drilled. The problem comes when you start drilling. Heat workhardens Inconel. Once you start drilling you cant stop and come back later, or you will keep braking drills. Too much pressure will brake the drill. I did this type of drilling years ago on a presision micro drill press. Its not easy, never use the same drill again or it will break. Try tapping fluid or oil as a lube.