Strength of tantalum to 276 GPa determined by two x-ray diffraction techniques using diamond anvil cells
A recent study published in the Journal of Applied Physics reports on the determination of the yield strength of tantalum to multi-megabar pressures. The work was a collaborative effort, led by student Christopher Perreault from UAB Professor Yogesh Vohra's SSAA partner group, with contributions from Lowell Miyagi and Sam Couper from the University of Utah CDAC partner group, and Larissa Huston, a postdoc from LANL in Blake Sturtevant's Tri-Lab partner group. A primary contribution of this work was the cross-validation of two independent methods for determining material yield strength at static high-pressure conditions.
Knowing the strength of a material under high pressure is important for understanding how that material will perform under extreme conditions. The strength measurement of tantalum (Ta) is useful for the many applications of Ta in industry and engineering. Two unique experimental methods exist for determining material strength under static high pressure in a diamond anvil cell: the linewidth method and radial diffraction. The linewidth method utilizes X-ray diffraction in the axial geometry (i.e. the incident x-ray beam is parallel to the axis of compression) and determines strength using the broadening of the diffraction lines. Radial diffraction uses the difference in the lattice strain observed for planes parallel and perpendicular to the axis of compression. In this study, the strength of Ta was determined using the two x-ray diffraction methods at HPCAT beamlines 16-ID-B and 16-BM-D.
In the three experiments reported in this paper, the yield strength of Ta is about 1 GPa at ambient pressure. When the sample pressure is increased to 50 GPa, the yield strength increases linearly up to 2.5 GPa. At higher pressures the yield strength was found to a maximum value of 9 GPa at a sample pressure of 276 GPa. These results are within agreement between all three experiments up to 60 GPa. Results from a toroidal DAC study with the linewidth analysis agree with previously published ramp compression data.
See: Christopher Perreault, Larissa Q. Huston, Kaleb Burrage, Samantha C. Couper, Lowell Miyagi, Eric K. Moss, Jeffrey S. Pigott, Jesse S. Smith, Nenad Velisavljevic, Yogesh Vohra, Blake T. Sturtevant, “Strength of tantalum to 276 GPa determined by two x-ray diffraction techniques using diamond anvil cells”, Journal of Applied Physics 131, 015905 (2022). https://doi.org/10.1063/5.0073228