An accurate understanding of the Sn phase diagram is needed to correctly interpret experiments examining ejecta, cavitation, and multiphase strength. A recently published multiphase equation of state (Rehn et al.) has suggested that δ-Sn (bcc) should form prior to incipient melt along the principal Hugoniot, with the two-phase region extending from nominally 57-73 GPa. This two-phase region lies at significantly higher pressures than previously anticipated based on previously reported shock release experiments. In this work, X-ray diffraction (XRD) was used to examine the phase evolution along the Sn Hugoniot from 30-85 GPa. The results of these experiments are presented and discussed in the context of the Sn phase diagram with an emphasis on the extent of the solid-liquid two-phase region and whether Sn melts from the δ phase along the principal Hugoniot.
*This work was supported by the U.S. Department of Energy through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract No. 89233218CNA000001). This publication is based upon work performed at the Dynamic Compression Sector, which is operated by Washington State University under the U.S. Department of Energy (DOE)/National Nuclear Security Administration award no. DE-NA0003957. This research used resources of the Advanced Photon Source, a DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357.
