Titanium allovs are more and more widely used in the aviation industry due to their high strength, good mechanical properies and strong corosion resistance. with the increasing proportion of titanium alloys in aircraft, the impact of numerical control of titanum aloy aerospace structural parts procesing eficiency on aviation manufacturina companies is also increasing. itanium alloy is a difficult-to-machine matenial. its relative machinability is 0.15 to 0.25, and the processing eficiency is only 10% of aluminum alloy, Therefore, the low processing efficiency of titanium alloy aerospace structural parts severely restricts the massproduction of modern aircraft. Achieving eficient machining of titanium alloy aerospace structural parts has become a common concem for aerospace manufacturing enterprises, CNC equipment manufacturers and tool manufacturers.
Cutting performance of titanium alloy.
itanium aloy has the charactenstics of good mechanical properies, strong corosion resistance and smallspecifc aravty, However in machining. the cutting peromanc of titanium alloy is very poor, mainy in the following aspects:
(1) High cuting force. Titanium alloy matenials have high strength and large cutting resistance during cutting which results in a large amount of cutting heat at the cutting edoe.
(2) Low thermal conductivty.Titanum aoy has low themal diftusivity, and a large amount of cutting heat is concentated in the cuing arear.
(3) The blade tip stress is heavy. itanium aloy has ow pasticik, and the chios generated by machining are very easy to bend resulting in a short contact lenath between the chips and the rake suface, so the unit area ofthe cuting edge has an increased fore, causing stres concentration at the tip
(4) High friction. Titanium aoy has a smallelastic modulus, which causes increased friction between the rake face and the fank face.
(5) High chemical activity At high cutting temperatures, titanium can easly react with gases such as hydrgen, oxygen, and nitrogen in the air to form a hard layer on the surace and accelerate tool wear. Efficient processing equipment for titanium alloy.
In order to meet the efficient processing of titanium alloy structural parts, the new titanium alloy processing equipment shows the following developing trends:
(1)High torgue. Titanium alloy has high strength and high cutting force during machining. One ofthe obvious characterstics of titanium alloy procesing machine tools is the large
spindle torque and swing angile torque.
(2) Aplication of electric spindle. High-power,high-torque electric spindles have been applied to titanium alloy processing.
(3)Horizontal machining center is used for titanium alloy processing, The horzontal machining center is convenient for chip removal. which is conducive to improving processing effciency and processing quality. The interchangeable workbench is easy to realize multi-station processing and set up flexible production lines to improve equipment utilization.
(4) High-pressure intemal cooling. During the machining of titanium alloy, the cutting heat is concentrated at the tip, which is easy to cause tool wear or damage. High-pressure internal cooling can accurately spray the cutting area to take away the cutting heat.