Microscopic Mechanism And Crystal Plasticity Finite Element Simulation Of TA15 Titanium Alloy At Deformation Process

Texture evolution during deformation for TA15 alloy were studied by Gleeble-3500 thermal simulation machine and electron back-scatter diffraction(EBSD). The results showed that there are significant changes in morphology and orientation of the ferrite with increase of deformation. The equal axis shaped grains are elongated. First of all, the region of orientation change occurs in the interior of equal axis shaped grains, and then it drives the whole grains to occur plastic deformation with the further increase of deformation. At the same time, The texture also has a obvious rotation during plastic deformation, a texture was weakened, and texture component was rotated from {1120} (1120) to relative stable{0001}<1126) .Experimental study based on isothermal compression with constant strain rate, exploring the effect of temperature, strain rate and the deformation percentages on flow stress and dislocation density during hot compression deformation of TA15 titanium alloy. The material flow stress increased with the increasing strain rate, and decreased with the increase of deformation temperature. In this research, TA15 alloy substructure of dislocation was analyzed after different treatments by using XRD linear Fourier analysis. The results showed that:The main types of dislocations are (1010), (0002) and (1011) type. The overall deformation density of dislocations is roughly within the range of 1011～1012cm-2. Above the phase transformation point, dislocation density decreases with the increase of deformation at strain rate of 1s-1. At 950℃, with the deformation increases, the dislocation density of every crystal plane decreases, and specially the dislocations of cylindrical and basal plane reduced faster with the increasing deformation. It obviously turns out that dislocations of cylindrical and basal plane are relatively easier to slip.A crystal plasticity finite element model (CPFEM) and the technology of (EBSD) has been developed to investigate the activation of the slip systems during compression of TA15 poly crystal at the temperature of 1050℃ and the strain rate 0.01s-1. The constitutive equations were embedded based on rate-dependent crystal plasticity in the software ABAQUS. The results shows that, the activation of the slip system are quite different. Both strain and stress show nonuniformity in the grains which are due to the nonuniformity of the activation of the slip systems. The inhomogeneous study of TA15 alloy deformation organizations during hot compression was processed with electron backscatter diffraction (EBSD).