Mechanical and microstructural analysis on the superplastic deformation behavior of two-phase ti-6a1-4v alloy

Abstract

Present investigation has been made to study the superplastic deformation behavior of Ti-6AI-4V alloy based on the theory of inelastic deformation, and m ana~.yze the boundary sliding characteristics by the use of transmission electron microscopy. The flow curves obtained by load relaxation tests at 600~ and 80(FC are fitted well with the inelastic deformation theory. It has been found that the deformation mode for the fine grained microstructures (3 Bin) is a type of iso-stress mode,-while that of coar,;e grained microstmctures (11 gm) is a mixed type of both iso-stress and iso-strain rate modes. The density of dislocations observed near the grain boundaries is higher along t~/[3 phase boundaries than the f~/~ grain boundavies, which confirms that the sliding resistance of a/~ is lower lhan that of c~/13.

Microstructure and Texture Evolution during Superplastic Deformation of SP700 Titanium Alloy

“…It is prone to exhibit excellent superplasticity while the volume fraction of the α phase is about 40~50% [ 15 , 17 ]. Moreover, the alloy with fine or ultrafine grain structure can obtain more excellent fracture elongation after superplastic tension than that with coarse or lamellae microstructure [ 18 , 19 , 20 , 21 ]. That is, the superplasticity of the alloy depends on various microstructural features like the grain morphology, grain size, and the volume fraction of the β phase [ 14 , 22 ], while the change of the texture can reflect that grain boundary sliding occurs in the alloy during superplastic deformation [ 23 ].…”

High Temperature Forming of Ti-6Al-4V Alloy Considering Microstructural Evolution

“…High-temperature forging and extrusion are widely applied in the aerospace industry. To produce complex shaped structural parts with defect free and homogeneous microstructure, it is essential not only to find optimum processing conditions at high temperature (mechanical aspects), but also to have clear understanding of microstructural evolution during the deformation (microstructural aspects) [1][2][3][4][5][6][7]. So far, many investigations have been carried out by use of finite element method (FEM) to predict the distribution of stress, strain and temperature of the deformed parts, but most of the works have ignored the effect of microstructural evolution during the deformation, which often misled the prediction revealing considerable deviation between experimental results and predicted ones.…”