The variation of microstructures, textures and mechanical properties from edge to center in cross section of Ti6242s titanium alloy

Abstract

Microstructures and textures determine the mechanical properties of metal materials. In this work, a Ti6242S bar with ϕ260*129 mm scale was selected to study variation of microstructures and textures from edge to center by Optical Microscope and X-Ray Diffraction. Owing to the less plane stress, fast cooling rate and complex flow stress, grains size are quietly fine and macrotextures are close to nearly random in edge, which lead to the most excellent and homogeneous mechanical properties. By comparing feature of microstructure in R/2 and center position, larger volume fraction of αs colonies formed in center. Meanwhile, the main texture components were (112¯0) [11¯00] and (112¯0)[0001] in R/2, but symmetrical cubic texture with very high intensity come into being in center. More and larger αs colonies combine high-density texture jointly cause tensile strength and yield strength drop dramatically in center. Young's modulus is mainly influenced by textures, due to different texture in different location, edge was the largest, following by the center and R/2. The spheroidization of αp laths was completed in edge by strain-induced but dynamic recrystallization in R/2 and center by analyzing grain boundary feature and misorientation of EBSD data.