Titanium alloy sheet must be produced by cladding rolling process

Titanium alloy has good room temperature, high temperature mechanical properties, excellent anti-fatigue and anti-crack growth ability, has been widely used in the manufacture of spacecraft missiles on the pressure vessel, rocket engine shell, aircraft skin, rib, web and other fields, is an important material for aerospace, aviation and defense industry. At present, the global demand for titanium alloy sheet is increasing. In the face of market demand, with the rapid development of the global aerospace industry and the application of new technology of superplastic forming and diffusion connection of titanium alloy sheet, the international and domestic demand for titanium alloy plate is increasing.

At present, most of the domestic production of titanium alloy sheet is still using the single sheet rolling method because of the low temperature plasticity of titanium alloy, cold deformation work hardening, using the single sheet production is extremely difficult. In order to make the rolling process proceed smoothly and reduce the temperature drop of the metal during the forging process, especially to reduce the chill of the billet surface, the forging titanium alloy die needs to be preheated. Otherwise, the temperature drop and surface chill of the metal will make the metal not fill the mold groove well and may lead to many cracks. The die preheating system for titanium alloy forging is usually detachable, but sometimes a heating device mounted on a press is also used. A detachable die heating system is usually a gas heater that slowly heats the die to the desired temperature range before the module is assembled into the forging equipment. The heating device installed on the press usually adopts induction heating or resistance heating.

According to statistics, in the production of Titanium Grade 5 alloy plates, the intangible loss caused by alkali pickling and grinding is as high as about 3O%, the comprehensive yield is only about 35%, and the production cycle is long and the performance is unstable. The deformation rate of its cold rolling degree is not more than 25%, and it needs many times of cold rolling and intermediate annealing, alkali pickling, and it is easy to appear in the rolling process defects such as cracks, cracks, slag dropping, and pits. Titanium alloy plate (less than 1.0mm) production process, titanium alloy cross rolling and β thermal process, self-developed laminated rolling and coating rolling process, titanium and titanium alloy warm rolling technology, self-developed atmosphere protection controlled cooling gravity creep orthopedic technology and other key technologies of the whole flow process. The test of TC4 sheet production new technology has been used to produce 0.6mm thick Ti Gr5 sheet by cladding rolling process, and has been put into mass production. Russia's AVSMA-VSMPO, the United States Active Metal Company (RMI) and Japan's NKK company all use the cladding rolling process to produce titanium alloy plates.