Machining Titanium

Evening all, before I commit to making several little bits form Ti I thought Id ask the more knowledgeable about machining it.
The parts I have in mind are: 1, a Bar about 3mm dia, 10mm long tapped M2 in each end and cross drilled 1mm in the center 2, flat plate with 3 M1.4 tapped holes in it
I have no idea what grade of Ti to make them from, thats on my list of things to find out. They are parts for a micro helicopter, currently made from alloy or steel.
Dave
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wrote:

Dave Hi, not as difficult to machine as many like to make out but it does benefit from a couple of particular techniques. In general, depending on particular alloy, you should use a cutting speed of at least 150 sfpm with a reasonable depth of cut and fairly high feed rate. We would have used something like 200 sfpm with a depth of cut no less than 0.010" and a feed rate of 0.006" per rev for finishing. While we used C2 grade carbide HSS is perfectly OK but must be kept very sharp, if you hessitate and the tool squeaks the tool will be blunt and the Ti might well work harden and be difficult to finish, With small diameter bar this speed might be difficult to achieve but you get the general gist. Tool sharpness is the most critical factor. Plenty of coolant and here your intended use is important, if you are going to use it in a fatique critical area then the type of coolant is critical. Soluable oil (at 15-1) works OK but for critical aerospace components avoid chlorinated oils. Dry machining is possible but it is quite possible to start a Ti fire and you wouldn't want that, believe me. Don't stop feeding when the tool is in contact with the work unless you want to re-sharpen. The material is quite flexible and will push away from the tool unless good support is provided.
Have a look here as it has been mentioned before and there are a couple of good links that cover the various grades and machining hints:
http://groups.google.co.uk/group/uk.rec.models.engineering/browse_thread/thread/92723b14b04db1ce/15de2a91a26931e6?lnk=gst&q=titanium#15de2a91a26931e6
best regards
Keith
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On Jun 19, 8:27am, jontom snipped-for-privacy@hotmail.com wrote:

Thanks Keith, good pointers. Guess Ill obtain some small bits and see how I go. :)
Dave
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