Research Progress Of Titanium And Titanium Alloy Profiles
Titanium and titanium alloy materials have many advantages such as low density, light weight, high specific strength, good low and high temperature performance, and excellent corrosion resistance. With the continuous expansion of the application fields of titanium and titanium alloys, titanium and titanium alloy profiles have been maturely used in fields such as eye frames and bracelets, as well as aviation, aerospace, marine, and chemical industries. Titanium and titanium alloys are susceptible to H, O, N and other gaseous elements, such as high processing resistance, narrow hot forming temperature range, etc., making it difficult to produce large-size and variable-section profiles, and the production cost is high.
At present, my country mainly produces some special profiles and variable cross-section titanium alloy profiles by mechanical processing, which leads to huge processing volume, low metal utilization and serious waste of resources. In contrast, the use of hot extrusion in a closed extrusion barrel has become an advanced method for producing titanium alloy profiles.
1 Status of titanium and titanium alloy profiles
1.1 Russia
Russia has carried out a lot of work on titanium and titanium alloy profiles. Since 1953, it has developed various titanium alloy profiles such as aero engine bulkhead profiles, wing profiles and wall panels. As early as 1965, it was established to produce 0T4 (Ti-4Al-1.5Mn), OT4-1 (Ti-2Al-1.5Mn), BT3-1 (Ti-6Al-2.5Mo-1.5Cr- 0.5Fe-0.3Si), BT6 (Ti-6Al-4V) and BT8 (Ti-6.5Al-2.53.3Mo-0.3Si) and other titanium alloy profiles hot extrusion process. Extruded thin-walled profiles mainly include 0T4 (Ti-4Al-1.5Mn), OT4-1 (Ti-2Al-1.5Mn), BT5 (Ti-5Al), BT14 (Ti-5Al-3Mo-1V) and other titanium alloy materials , Extrusion variable section profiles mainly include BT3-1 (Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si), BT20 (Ti-6.5Al-1Mo-1V-2Zr-0.15Si), BT22 (Ti- 5Al-5Mo-5V-1Cr-1Fe) and other high-strength titanium alloy materials, typical mechanical properties of titanium alloy profiles.
Russia’s research results on titanium alloy profiles show that the use of the stretching method to finish extruding thin-walled profiles can improve the surface quality of the profiles by one level and reduce the dimensional tolerances by one third; The metal utilization rate is doubled, and the machine addition is reduced by four-fifths.
1.2 United States
Beginning with the industrial production of titanium in 1948, in 1950 the United States used titanium alloys for the first time on F-84 fighter jets to make non-load bearing components such as heat shields, wind deflectors, and tail shields. With the industrial development of titanium, the United States The application research of titanium alloy profiles began using hot extrusion technology, especially since the first practical titanium alloy Ti-6Al-4V was successfully developed in 1954, the American titanium industry began to develop rapidly.
In the research of titanium and titanium alloy profiles, as early as 1968, special production specifications for aviation titanium and titanium alloy profiles were formed, mainly including CP-1, CP-2, CP-3, CP-4, A-1 (Ti-5Al-2.5Sn), A-2 (Ti-5Al-2.5Sn ELI), A-4 (Ti-8Al-1Mo-1V), AB-1 (Ti-6Al-4V), AB-2 ( Ti-6Al-4V ELI), AB-3 (Ti-6Al-6V-2Sn), AB-4 (Ti-6Al-2Sn-4Zr-2Mo) and other titanium alloy materials. At present, RMI Corporation of the United States holds large-scale titanium The leading production level of alloy profiles, the titanium alloy profiles produced are widely used in aviation, aerospace, petrochemical and other fields. Typical mechanical performance requirements for titanium and titanium alloy profiles.
2 .Conclusion
(1) As a semi-finished part with a near-net shape, titanium alloy profile has a small machining allowance, high structural benefit, excellent comprehensive performance, and has great market potential.
(2) At present, some of the titanium alloy profiles for civil use in my country can be made domestically, but the titanium alloy profiles for aviation and aerospace that are demanding for service conditions mainly rely on imports and are easily restricted by various conditions. With the rapid development of my country's aviation and aerospace industries, it is urgent to establish a stable production process for the mass production of titanium alloy profiles required for key parts, and formulate unified production specifications and inspection requirements for quality judgment.
(3) my country should focus on the lubrication conditions, metal strain state and flow behavior in the hot extrusion deformation of complex cross-section titanium alloy profiles on the basis of having mastered the production technology of some simple-section titanium alloy profiles.
(4) In recent years, my country has been keen to develop new alloys and expand new processes in the development of titanium alloys, but the continuous exploration of the performance potential of old-brand titanium alloys is obviously insufficient. Various problems will be encountered in the process of product development and upgrading. The control of comprehensive performance also has shortcomings.
