Titanium
- Thread starter Slasher
- Start date
Thanks, any ideas on lathe speed.
oops I just noticed I posted in the wrong section
Titanium is tough but its not really super hard. I thought Iconel and Monel were much worst to machine.
Look online and and you should find a speed and feed chart. Or look in a Machinist Handbook
Like been said , do a search, but my experience with Ti is that it is like machining 316 stainless, but at lower surface speeds.
I like to use the centre point sharpened drills like the Titex brand or the Precision brand.
For drilling I use 8m/min or slighly less (25 ft/min), so a 1/8 drill will be 800 rpm max with a flood coolant.On a manual lathe I would run it at 500 rpm and use a high feed rate, like close to .1mm per rev
Clearly with the high feed rate, you do not want the tool out any further than required.
Dwelling in the cut is really bad as this will work harden the material. Ti is really bad conductor of heat, so cooling the centre point in drilling is always difficult unless you use the through coolant drills.
As soon as the drill starts to dull, takes more pressure to push it through when drilling, stop. Resharpen and have another go. Otherwise you end up making a mess of things.
For the OD turning I like the positive rake tools like what is used to turn Ali. Again I use quite a low speed but use a high feed rate, again plenty of coolant.As a rule of feed rate I use upto 1/2 the radius of the tool as the feed rate. Using a 0.4mm rad tool (1/64) use 0.2 mm /rev feed rate (0.008 inches/rev) for finish cuts I use 0.08mm/rev (.003 inch/rev). I like to make finish cuts at 1/2 the tool radius deep per side or the tool radius on diameter. So a 0.4mm rad tool, finish pass is 0.4mm on diameter (0.2mm per side depth of cut). Again sharp tools work best. Yes it will string if conditions are not correct. A method around the stringing is to vary the feed rate and increase then decrease.Easy to do on a manual lathe, a real pain when programming a part though.
I like to support the part as much as possible and where ever possible, I drill the inside 1st,then use a steady for the outside passes.
There are soluble coolants made specifically for Ti .They work a lot better than the run of the mill coolants in my view.
Have fun, Neil
I like to use the centre point sharpened drills like the Titex brand or the Precision brand.
For drilling I use 8m/min or slighly less (25 ft/min), so a 1/8 drill will be 800 rpm max with a flood coolant.On a manual lathe I would run it at 500 rpm and use a high feed rate, like close to .1mm per rev
Clearly with the high feed rate, you do not want the tool out any further than required.
Dwelling in the cut is really bad as this will work harden the material. Ti is really bad conductor of heat, so cooling the centre point in drilling is always difficult unless you use the through coolant drills.
As soon as the drill starts to dull, takes more pressure to push it through when drilling, stop. Resharpen and have another go. Otherwise you end up making a mess of things.
For the OD turning I like the positive rake tools like what is used to turn Ali. Again I use quite a low speed but use a high feed rate, again plenty of coolant.As a rule of feed rate I use upto 1/2 the radius of the tool as the feed rate. Using a 0.4mm rad tool (1/64) use 0.2 mm /rev feed rate (0.008 inches/rev) for finish cuts I use 0.08mm/rev (.003 inch/rev). I like to make finish cuts at 1/2 the tool radius deep per side or the tool radius on diameter. So a 0.4mm rad tool, finish pass is 0.4mm on diameter (0.2mm per side depth of cut). Again sharp tools work best. Yes it will string if conditions are not correct. A method around the stringing is to vary the feed rate and increase then decrease.Easy to do on a manual lathe, a real pain when programming a part though.
I like to support the part as much as possible and where ever possible, I drill the inside 1st,then use a steady for the outside passes.
There are soluble coolants made specifically for Ti .They work a lot better than the run of the mill coolants in my view.
Have fun, Neil
Yes! Now if you ever have a small Titanium fire...never pour water on it.
Where I used to work, titanium chips started burning in the exhaust duct and almost burnt down the building..... they put water on it.......... bad idea.
Kim
Does Titanium burn? I don't remember that.
I remember machining Magnesium and we kept a bucket of sand close by just in case it caught fire. I would save up all the chips until a had a floor dry bag full and take it outside and light it up. Burned white hot.
Oh yes, titanium burns. It's been a long time...back in 1974 I used to machine a lot of titanium. If I remember right, it was a bright light blue color. It was a good reason to keep your machine clean.
That was when I went through my apprentice program. We used to machine almost every metal there was. I still have some chips when I was machining 99.9% silver...LOL. I save everything. Hoarding is just one of my problems.
Wow, thanks for the detailed reply :thumbup:
and also to all the others for your help. :smile:
Oh yes, titanium burns. It's been a long time...back in 1974 I used to machine a lot of titanium. If I remember right, it was a bright light blue color. It was a good reason to keep your machine clean.
That was when I went through my apprentice program. We used to machine almost every metal there was. I still have some chips when I was machining 99.9% silver...LOL. I save everything. Hoarding is just one of my problems.
I gotta know, what happens if you put water on it does it burst/explode ?
From what I understand, the Ti and Mg fire occur from the machining operation when the chip temperature is hot enough to ignite the residual oil from the coolant.
I have worked with a lot of Mg and never seen a fire,(that is a good thing)
I have always flood cooled my parts being manufactured, in the case of making Mg and Ti parts, I keep the oil to water concentration close to 10%.
As a guide, if the water on the surface of what you are making is bubbling or showing water vapour, your cutting tools are dull or the speeds and feeds are way off the ideal target.
You should not be cutting these materials in a dry state anyway.
Clean water , adds oxygen to the metal fires . The coolant in a metal fire adds both a fuel and oxygen.
Contaminated coolants can also lead to problems when using Mg. I can't remember which way it goes, ph higher than 8 or lower than 6 , makes the material want to oxidise more easily and so becomes a greater fire risk .
I have worked with a lot of Mg and never seen a fire,(that is a good thing)
I have always flood cooled my parts being manufactured, in the case of making Mg and Ti parts, I keep the oil to water concentration close to 10%.
As a guide, if the water on the surface of what you are making is bubbling or showing water vapour, your cutting tools are dull or the speeds and feeds are way off the ideal target.
You should not be cutting these materials in a dry state anyway.
Clean water , adds oxygen to the metal fires . The coolant in a metal fire adds both a fuel and oxygen.
Contaminated coolants can also lead to problems when using Mg. I can't remember which way it goes, ph higher than 8 or lower than 6 , makes the material want to oxidise more easily and so becomes a greater fire risk .
A titanium fire will flare up when water is put on.
I think this might of happened in this video.
Firemen might not of been properly trained in this type of fire.
http://www.youtube.com/watch?v=NDhnwLheoU4
With cue making, you'll never have to worry about a titanium fire.
When doing production runs in a factory, a cutting tool can get dull and chip off without much warning and then cause a fire in your chips. Of course there may be some sparks and heat after the cutting tool fails.
magnesium
I have a little fire starting tool/kit that has a bar of magnesium and a file and you chip off pieces of mag and ignite with a flint type spark igniter.
It's for boyscouts or something like that. Kinda cool... two bucks...
I have a little fire starting tool/kit that has a bar of magnesium and a file and you chip off pieces of mag and ignite with a flint type spark igniter.
It's for boyscouts or something like that. Kinda cool... two bucks...
One notable exception to that would be aluminUM.
At 1100*F it's liquid. I've never seen it burn.
KJ
Went through an induction at a place that does Ali extrusions. In the video was a piece about a small amount of liquid left in a soda can that was placed into the ali scrap bin just prior to it being added to the furnace.
The main lot of material had been pre heated so moisture was not present, but not the soda can.
The result was an explosion killing quite a few people from the molten metal going everywhere.This happened in Australia but can not remember the year.
As a result, some places do not have sprinkler fire systems and if there is a fire, it is recommended that it burns itself out.Just get as many people out of the building as quick as possible. These places have policies of no drinks in the vacinity, no lighters etc,and regular fire drills.