J. W. Elmer, Lawrence Livermore National Laboratory, Livermore, CA; T. A. Palmer, The Pennsylvania State University, University Park, PA; S. Babu, Edison Welding Institute, Columbus, OH; E. D. Specht, Oak Ridge National Laboratory, Oak Ridge, TN

Summary: In-situ X-Ray diffraction experiments were performed at the Advanced Photon Source (APS)using synchrotron radiation to directly observe the alpha to beta phase transformation in Ti-6Al-4V under controlled heating and cooling conditions. Real time measurements of the alpha/beta phase ratios and lattice parameters help understand this important phase transformation sequence to gain a better understanding of HAZ development in titanium alloy welds.