Mathematical modeling of processes of pressure treatment of industrial titanium alloys in the superplasticity state

Abstract

A variant statement is formulated for the boundary problem of mechanics of superplasticity (SP). The variant is aimed to the development of mathematical models of technological processes of SP formation of industrial titanium alloys. It involves determining relations of the theory of creep with internal variables responsible for the description of evolution of the material structure during the SP deformation. As examples, technological processes of superplastic shaping of commercial sheet titanium alloy VT6s (Ti-6% Al-4% V) in the SP state are considered. Identification of determining relations is carried out by the results of technological experiments. To solve the boundary problem, a packet of applied programs ANSYS is used; calculations are performed for various variants of the selection of a mesh of final elements and fastening conditions. The results of calculations are compared with the experimental data for the commercial titanium alloy VT6s and calculations by engineering procedures. In the course of the analysis of obtained solutions of the boundary problem of mechanics of SP, it is found that the previously suggested engineering approaches can be applied in practice under the conditions when the selected loading modes correspond to the realization of the optimal temperature and dynamic conditions of manifestation of the SP effect.