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tolerance issues with Titanium clad

Crowndroyal

Plastic
Joined
Jun 3, 2019
Location
Sarnia
Working on a project, which is a tube sheet that is carbon with titanium clad. Cladding is about 0.500 (+/-) 0.050.


Spot drilling the titanium to depth till I hit carbon at 752 rpm and feed is 4.2 with 0.760 iscar tip, carbon is then drilled at 1800/18 with a 0.759 Kena tip ( don't ask why ) Tolerance on holes are 0.758 +0.004 -0.002.


The ( GO/NO GO gauge ) wont go through the majority of the holes, it either stops near the top of the hole or near the bottom almost never in the middle of the hole.

any suggestions on changes for speeds and feeds ?
I have suggested drilling and reaming/honing or using a flex hone suggestion being ignored.
 
get an actual dimension on the nogos, how much are we talking about? is it an out of round condition that is causing it? to solve it you need to diagnose the nature of the problem in a little more detail.
also, has a hand reamer been tried?
 
Never cut that kind of stuff. It sounds horrible.

I would drill it undersize and interpolate it with an endmill.

I assume the GO is the only pin that won't go?? Are the pins the actual high/low of the hole size? I only ask because I often set go/nogo pin gages a thou or 2 above/below the actual tolerance just as a preventative measure.
 
Sorry forgot to mention the numbers on the gauge figured that could have been found out with the tolerances given. gauge is for go 0.756 no go is 0.761.
Also using a 0.758 drill body, what I am assuming is that the 0.760 iscar inserts have a different pitch then the 0.759 kena inserts and with the drill body and kena insert being smaller its drifting, went with a smaller body as the titanium was leaving build up on the drill body which was giving issues as well. over 8000 holes need to be drilled.


drilling on a Intimidator 120 as well sorry for the loss of info, hand reamer was not tried but a flap wheel type thing was, I tried suggesting flex hone but "I know nothing" we did " core drill once it was off the machine but was still having issues obviously because it was a core drill and not a reamer.


EDIT: aluminum channel is set up under the work piece 6" 1/8" thick set up underneath like ( U ) piece ontop the U.


I would drill it undersize and interpolate it with an endmill.

would there not be flex in an endmill long enough to plunge through 3.5" hole depth ?
 
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Crowndroyal do you have link to the material ?

Sorry to be ignorant but sounds like an awesome material / composite … This is not Carbotanium but CF tubes clad in sheet titanium into structural shapes ???

I'm having to learn about similar tooling so happy to follow everybody down the rabbit hole.

:cheers:
 
Never messed with stuff like that but I wouldn't use 2 brands for the same hole. The reps will just blame the other brand (likely both rightfully so). Pick one brand, have the rep come in, and tell you what/how to run it. Drilling dissimilar stackups is likely something the reps have been trained on. If the higher ups won't take your advice they might listen to the rep.
 
Never messed with stuff like that but I wouldn't use 2 brands for the same hole. The reps will just blame the other brand (likely both rightfully so). Pick one brand, have the rep come in, and tell you what/how to run it. Drilling dissimilar stackups is likely something the reps have been trained on. If the higher ups won't take your advice they might listen to the rep.

it's a back order issue with the inserts or delayed shipping wasn't given the info on that otherwise we would be using the iscar already,, PS I am just a button pusher who knows nothing according to the lead hand, or at least that's how he seems to treat me.
 
...Spot drilling the titanium to depth till I hit carbon at 752 rpm and feed is 4.2 with 0.760 iscar tip...

it's a back order issue with the inserts or delayed shipping wasn't given the info on that otherwise we would be using the iscar already..

Tip or insert? SumoCham? Which tool exactly are you using for the first material? Could you use the same tool all the way through just changing speed and feed? I bet a SumoCham ICP would make it. Through coolant? PSI?
 
Tip or insert? SumoCham? Which tool exactly are you using for the first material? Could you use the same tool all the way through just changing speed and feed? I bet a SumoCham ICP would make it. Through coolant? PSI?

yes sorry its a drilling inserts for indexable heads , using the iscar SumoCham tip for the Titanium, cant use the same tip as when we get into the carbon wrap up occurs as the cutting edges are different for the carbon yes using through coolant. although I do not think we have used the .760 sumo all the way through we are also very limited on the sumocham inserts but have a stckpile of the kenametal HP and spl's
 
I've never done ti clad, but I've done a fair bit of inconel clad.

There are two discrete challenges:

• Cutting inline through two extremely different materials, while maintaining size and finish.
• Dealing with the uncertainty of the position of the layer transition.

The second problem has usually forced me into abandoning any plans of using separate tools per layer.

The times I've done this I've always ended up with a single undersize drill, feeds and speeds for the tougher material - dealing with the chip forming problems that occur in the soft core - and then single point boring to finish.
 
I've never done ti clad, but I've done a fair bit of inconel clad.

There are two discrete challenges:

• Cutting inline through two extremely different materials, while maintaining size and finish.
• Dealing with the uncertainty of the position of the layer transition.

The second problem has usually forced me into abandoning any plans of using separate tools per layer. ( we are spot drilling fairly deep and then using copper something "lost the second word". blue liquid to tell if we are through the titanium clad. its not every hole coming out undersize only about 4 to 20% out of every 500 holes, totally random from what I have seen.

The times I've done this I've always ended up with a single undersize drill, feeds and speeds for the tougher material - dealing with the chip forming problems that occur in the soft core - and then single point boring to finish.




well I cant even suggest anything to the main lead hand, as he has a massive chip on his shoulder and is extremely arrogant.
You are always wrong and in the off chance you are right or speak up and say anything you get a spew about thinking you know everything. I don't know everything never claimed I have but I at least try and think of why things are not going right and open to any suggestions from co-workers that might just help solve the problem.

Like this guy is so arrogant we got into an argument about coolant FFS. He seems to think there is hydraulic fluid getting into the coolant and that is what stays on the table, floor, work piece where ever the coolant has been and I tried telling him its the coolant after water has evaporated from it and he went on a huge rant about no way that's possible its gotta be something else then when I wouldn't let up and simplified it down he got all angry shakes his head and walks away cause I wouldn't agree with him.

My experience comes from manual drilling I am no cnc guru single point boring ? I am assuming that is 1 cutting edge taking material out all the way around and through while in a drilling motion.


So it's titanium clad carbon steel, not titanium clad carbon (graphite or fiber). I think that's confused a few people.
Oh sorry assumed since we usually cut metal we would know what carbon was referencing sorry.


Maybe a little bit...


I guess I assumed the part was 1/2 thick. not 3.5" thick.


If it stayed in tolerance I wouldn't care if there is that bit of flex, I cant imagine it being enough to totally throw it off if were only doing a 0.05 cut or something with the endmill.
 
So it's titanium clad carbon steel, not titanium clad carbon (graphite or fiber). I think that's confused a few people.

OH. Yeah, I was figuring it was some carbon fiber sandwiched between some sheets of titanium, and it was only 1/2" thick.

Turns out it is 3.5" thick steel with the titanium being 1/2" thick on each side. Big difference. Possibly easier, though.


To the OP:

Now, I don't see an issue with drilling undersize and reaming the whole thing?

Or interpolate near depth, and ream the rest?


Sounds like your superiors won't have you implementing any of it anyway?
 
OH. Yeah, I was figuring it was some carbon fiber sandwiched between some sheets of titanium, and it was only 1/2" thick.

Turns out it is 3.5" thick steel with the titanium being 1/2" thick on each side. Big difference. Possibly easier, though.


To the OP:

Now, I don't see an issue with drilling undersize and reaming the whole thing?

Or interpolate near depth, and ream the rest?


Sounds like your superiors won't have you implementing any of it anyway?

Reaming ti is miserable to do.
 
Reaming ti is miserable to do.

Yeah, but he's got a .006" limit. And I don't see anything about finish.

We reamed 2" thick grade 5 Titanium a few years ago, similar size hole (was thru hole for 3/4 pin, needed to be about .755 i think). We used one of those resharpenable carbide tipped reamers. You know, the kind with the tapered head screw in the end. You know, the kind that says the screw is only to allow for resharpening and should never be used to adjust size.

Does anyone actually listen to that suggestion?

I think you could get one of those to cut .010" over. And the cutting edge will have a reasonable amount of back taper to help avoid chips from smearing around.

Although, I would imagine that there's some weird material properties right there where the steel and titanium weld together. I know I heard about this kind of material in school but I've never cut it.
 
I would think if you drill a hole in one part and it comes out undersize, then the next part is perfect, it feels to me like coolant related, or inappropriate process for the coolant you have.

As mentioned, it would be helpful to know 'what' the error is. Running a reamer through would probably show you, out of round, burr, whatever

That said, expecting a hole diameter to be correct better than 1 percent with a drill is probably wishful thinking. I would not expect a 1/8 drill to give me a hole +-.0005 with a drill.

So you are going to have a tool change in there, the only remaining question is what tool that is.
 
OH. Yeah, I was figuring it was some carbon fiber sandwiched between some sheets of titanium, and it was only 1/2" thick.

Turns out it is 3.5" thick steel with the titanium being 1/2" thick on each side. Big difference. Possibly easier, though.


To the OP:

Now, I don't see an issue with drilling undersize and reaming the whole thing?

Or interpolate near depth, and ream the rest?


Sounds like your superiors won't have you implementing any of it anyway?

the tube sheet is is 3.5" thick in total and only half an inch of it is titanium which is only the top layer.
 








 
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