Analysis of deformation behavior and microstructure of a near-alpha titanium alloy in single phase region

Abstract

Abstract In the current work, deformation behavior and microstructure changes of a new near-alpha titanium alloy in single phase region are investigated. For this purpose, high-temperature compression is carried out in single-beta phase region with different temperatures, strain rates and height reductions. The flow softening behavior can be observed at the strain rates of 0.01s−1 and 0.1s−1, whereas work hardening occurs at the strain rates of 1s−1 and 10s−1. The extents of softening or hardening are strongly influenced by strain rate, but vary only slightly with deformation temperature. Recrystallization and recovery have different impacts under different conditions. Recovery plays a dominate role particularly under high strain rate. By contrast, recrystallization controls microstructure evolution under low strain rate. Alpha phases are precipitated from prior beta grains during cooling after deformation, and there is truly a link among alpha phases. The EBSD analysis indicates that the two adjacent precipitations of alpha may share one common or close (11–20) pole, but the caveat is that the statement is not rigorous due to the smaller scanning areas. Additionally, the drive forces of growth of alpha phases are influenced by their crystal orientations. For the two accompanying alpha phases, it seems the interspersed alpha phase tries to pass through the surrounded alpha phase and grow into a longer structure when they have one common (11–20) pole, while it may be difficult to grow longer when one of (11–20) poles of them have some deviation.