Milling titanium

dodoknives225

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Hey guys so looking for some help.....basickly I have a piece of titanium .160 thick bu 1.5in wide and 10 inches long. So I want to mill 1 half of it down to half thickness so one end of this bar will stay at .160 and the other half will be milled down to .08 I have a 2 in indexable end mill to accomplish the job...so I just started and I tried to go at a normal speed feed rate , a VERY slow feed rate even taking thin cuts at once or deeper cuts but no mater what I did it was throwing sparks everywhere until I just called it and stoped I was using a lil kool mister for lube but I think I may need a flooder to keep the sparks down does any one here know any decent flooders at a decent price or any sugestions would be appreciated! Thanks guys
 
Pure Ti, 3Al/2.5V, and 6/4 alloys are all easy to machine. You should be getting long, springy chips coming off, and a buttery feel through the handwheels... sounds to me like you got some blade titanium or an oddball alloy. It's worth trying to ID that stuff if it's throwing sparks under carbide.

Edit: this pure Ti ball cut like butter.
f07cfb812f7c8a88b49023d694ec455f.jpg
 
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Ti in my experience likes positive rake an aggressive feedrate. It tends to workharden if you baby it.
 
What Surface Feet are you running? I would start at 100 SFM, that would be around 191 RPM for the 2 inch indexable end mill you are using.

Kevin
 
Been checking into that lately and the consensus I get is keep the feed rate up (as tony said) but slow the cutter speed (sfm)
Try normal feed rate with less rpm. Try a new spot on the bar as you may have work hardened your original spot.
 
ok thanks guys so I do know 100% it is 6al-4v titanium I am a knife maker and I use it as a liner or frame of a folding knife and that is part that the lock is made out of so it needs to be very springy and 6al-4v works perfect and I only get it from 2 sources both of wich have the alloy marked...

I just ordered a coolant system from grizzly and I have a grizzly knee style mill so it should fit right in pretty easy...the mister I have now I just don't think it its spraying enough water

Now what you you guys sugest a friend that is teaching me how to do this sort of knife says he used to use .140 and he would mill it half thickness so he would take off .07 off of half on the bar now he told me that he would take off that whole .07 in 1 pass! I tried to do that a couple days ago and not only did I get a lot of sparks but the machine was making a awefull banging sound coming from the spindle area also when I stoped because of the sound and pulled back the milled surface was not flat and smooth at all.....so this time I tried taking smaller slices and yeh if I took off .01 it didn't spark that much but if I kept at that pace it would take forever so I slowly started to take deeper and deeper slices and by the time I got to a point where it was feasible to do without making a million passes sparks were flying in every wich direction...not sure if you ever seen it and I forget the name but as a kid we played with these fireworks and one of them you would lay on the ground and it would spin as it threw out sparks that is exactly what happened here but this was in my garage so not trying to burn the house down
 
My Granddad started up a shop in the 60's making flight control systems for the Bell Huey. The clevis on the end was Ti, I spent many hours running those though a hori mill. Lots of coolant.... I took a piece into school (we have a vocational school , Jr & Senior yr and it's great!)
I let the guys have their try at turning it, LOL. Their high speed bits just melted. I still have that piece.
 
You only need to move 0.040 per side to get to 0.080. With the right tooling, one pass is probably your best bet. I don't know your setup or mill, but that's not really a heavy cut.

If you have 5" of it just hanging in the air outside a vise, there will be lots of vibration/harmonics/chatter all working against you. You have any pics of your setup?
 
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