Titanium alloy is a new metal developed in recent years and is widely used in various industries. Because of its low thermal conductivity, cutting emperature is much higher. For example, it is higher almost twice than 45 steel in the same cutting force.　　

At the same time, due to the reason of the affinity of titanium alloy, titanium chips and cut surface easy to tool material bite surface produced serious knife phenomenon at high cutting temperature, which is considered as the second high temperature alloy than the hard cutting material.  This paper below will introduce in detail how to turn titanium alloy.　

1, Titanium alloy cutting tools　　

The YG type cemented carbide with high thermal conductivity, good bending strength, small grain size and small affinity with titanium should be used for turning titanium alloys. In addition to ordinary HSS, high vanadium HSS, cobalt HSS and aluminum HSS should be used to improve tool durability. Titanium alloys can also be turned with diamond or synthetic polycrystalline diamond and cubic boron nitride as cutting tool materials.　　

According to the properties and cutting characteristics of titanium alloy, the geometrical parameters of turning titanium alloy tools should be considered from improving the heat dissipation condition, increasing the edge strength, and reducing the phenomenon of cold and stick.　　

2. Accuracy, conditions and correct cutting parameters　　

The beat accuracy of the tool in axial and radial direction is also important. For example, the cutting edge around a milling cutter can quickly become damaged if the blade is not fitted correctly into the cutter. When cutting titanium alloy, some other factors such as poor tool manufacturing tolerances, wear and tool damage, defective or poor tool handle quality, machine tool spindle wear and so on can greatly affect the service life of tooling.　　

Although the positive front angle slot are preferred to use in most workshop. But the fact is that the slightly negative front angle slot can remove the material with a higher feed and up to 0.5mm per tooth. On the other hand,  it also means that the best stable state must be maintained, that is the machine tool should be very strong and the clamping should be extremely stable.

3. Cutting parameters　

Too high or too low cutting temperature of titanium alloy will reduce tool durability. Therefore, strive to choose the best cutting temperature corresponding cutting speed. The best cutting temperature of high speed steel tool is between 480 and 540℃. Besides,  the best cutting temperature of hard alloy tool is among 650 to 750)℃. In general, the corresponding cutting speed of HSS tool is in 8 -- 12m/min. The cutting speed of synthetic POLY crystalline diamond tool is 100m/min for dry cutting and 200m/min for wet cutting. When the hardness and cutting depth of the work piece material is large, the cutting speed should be correspondingly smaller.

4. Cutting fluid　　

When turning titanium alloy, emulsion with good cooling effect or aqueous solution with extreme pressure additive should be used in order to reduce the cutting temperature and  prevent the combustion of titanium alloy powder during micro-turning.