Evolution of Lattice Strain and Phase Transformation of Beta III Ti Alloy During Room Temperature Cyclic Tension

In-situ tensile test was carried out at beam line 11-ID at APS, Argonne National Laboratory, to understand the deformation mechanism of beta III Ti alloy. An annealed material was cyclic loaded to certain strains and return to zero stress with the evolution of lattice strain and phase transformation monitored by synchrotron x-ray diffraction during deformation.  This experiment provides the direct evidence of Stress Induced Martensite (SIM) phase transformation of beta III during room temperature deformation. The evolution of phase transformation during loading and unloading, and its influence on the internal strains and the macroscopic mechanical behavior will be discussed.