Relationship between mechanical properties , microstructure and parameters of thermomechanical processing under complex loading conditions in titanium alloy Ti-6.5Al-3.5Mo-1.6Zr-0.27Si

摘要

The process of lamellar microstructure transformation into an fine grain equiaxial one in two phase titanium alloys is determined not only by the temperature-strain rate parameters of deformation but also by the mode of loading. The experimental results obtained by the investigation of the influence of one- and two-component loading onα-phase morphology and mechanical behaviour of the two-phase Ti-6.5Al-3.5Mo-1.6Zr-0.27Si titanium alloy are given in the present paper. Preliminary deformation changes significantly both the microstructure type and the mechanical properties of the alloy. The microstructure transforms from coarse lamellar type to equiaxial one. Further deformation in the temperature-strain rate condition of superplasticity decreases significantly flow stress and increases ductility of the alloy. The most noticeable effect of microstructure transformation is resulted from deformation conducted by the mode of proportional loading .