The paper describes the results of comprehensive studies of the microstructure, mechanical and technological properties (formability and weldability in the solid state) of the titanium sheet alloy VT6 (Ti-6Al-4V) with improved superplastic properties produced by PSC «VSMPO-AVISMA». In the first part the initial microstructure of the alloy and its mechanical properties over a wide temperature range from 650 to 900°C at strain rates of 4×10 -4 , 4×10 -3 and 4×10 -2 s -1 have been investigated. It is found that the initial microstructure of the sheet is uniform and ultrafine grained with an average size of 1.2 μm. The initial grain size of the microstructure is varied from 0.1 to 4 microns. Most of the grains have a size from 0.5 to 1.5 microns. Mechanical tensile tests revealed that the ultrafine grained titanium alloy VT6 possesses higher superplastic characteristics as compared with those of the standard VT6 sheet. The microstructure of deformed samples and data on changes in the grain size depending on the temperature and strain rate are investigated and represented. The comparison of the superplastic characteristics of the samples cut along and across to the rolling direction indicates the absence of anisotropy. The studied alloy exhibits the best superplastic properties at temperatures ranging from 700 to 850°C and strain rates of 4×10 -4 -4×10 -3 s −1 , which corresponds to the manifestation of the low-temperature superplasticity. Superplastic elongations are from 650 to 1075 %. That allows us to recommend the produced sheet alloy for development of low temperature processing methods based on superplastic forming and diffusion welding to manufacture the parts for aerospace industry.

The superplastic forming process of the VT6 titanium alloy three‐layered hollow structures with goffered filler are investigated. Based on the results of experimental studies and on the results of finite element modeling, we determine rational parameters of the process such as gas pressure increase rate, when superplastic flow condition is satisfied for ribs, and the processing time is minimal.

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The manuscript considers microstructure, mechanical and processing properties (formability and solid state weldability) of sheet titanium alloy VT6(Ti-6Al-4V) with improved superplastic properties production of JSC «VSMPO-AVISMA Corporation" for the process of superplastic forming at low temperatures and new experimental cheaper sheet titanium alloy VST2k. Complex studies of microstructure, mechanical properties, formability and weldability in the solid state of these titanium alloys were carried out. Studies have shown that both alloys in the temperature range 750-850oC have good weldability in the solid state and exhibit good superplastic properties. Technological properties of the alloy VST2k almost as good as the properties of the alloy VT6. This makes it possible to recommend the sheet alloy VST2k along with the alloy VT6 for the manufacture of hollow structures by SPF/DB in low-temperature superplasticity.

The work is devoted to the development of the production of three-layered hollows structures made of VT6 titanium alloy by means of superplastic forming (SPF). Based on the numerical results the pressure cycle was determined to satisfy the superplastic flow condition in the stiffening ribs and to minimize the forming time.