Machining of titanium alloy structural parts

The processing difficulties of titanium alloy structural parts and the influencing factors of processing deformation of weakly rigid structures are presented. The control method of processing deformation of weakly rigid structural parts is proposed from the selection of machine tools, tool selection, and effective cooling. Titanium alloy materials have excellent properties such as lightweight, high strength, and high-temperature resistance. For example, using TC18 titanium alloy instead of high-strength structural steel for landing gear can reduce the weight of the aircraft structure by about 15%, so it is the main bearing of advanced foreign aircraft. A large number of new high-strength titanium alloys are used in the force parts. For example, Titanium Alloy Threaded Rod accounts for about 21% of the body structure materials of the American B-1 bomber; the titanium content of the Russian Il-76 aircraft reaches 12.5% ​​of the body structure weight. , From the development trend, the use of titanium alloys in Europe and the United States is gradually increasing, and it also shows that a large number of titanium alloys are used, especially some new titanium alloys have become the development direction of aviation design. However, most aerospace products use thin-walled parts, which are relatively complex in structure and require high precision. Due to the thin wall, the rigidity of the parts is poor. Under the action of cutting force, it is easy to produce bending deformation during processing, and the wall thickness is inconsistent up and down, resulting in out of tolerance. . At present, the commonly used method in enterprises is repeated milling in finishing. Due to the small thermal conductivity of titanium alloy, low elastic modulus (about 1/2 of steel) and high chemical activity, the small allowance cannot be milled at all, often The phenomenon of "less cutting" occurs. In order to ensure the size of the parts, it can only be polished by hand, which greatly increases the processing cycle of the parts, and may cause the surface of the parts to burn.