Application of radial x-ray diffraction to determine the hydrostatic equation of state and strength of TiB2 up to 60 GPa -: art. no. 023522

Room temperature investigations of the shear strength of hexagonal TiB2 have been performed in order to determine the hydrostatic equation of state of the material up to 60 GPa using radial x-ray diffraction in a diamond anvil cell. We have analyzed the deformation mechanisms under pressure by analyzing the (001) and (100) peaks in the powder diffraction data, and we have deduced the hydrostatic equation of state of TiB2. The uniaxial stresses in the (100), (001), and (101) diffraction planes show a large pressure dependence, indicating a significantly large anisotropy in the material. The stress in the (001) plane shows the largest increase with pressure and reaches a maximum value before the other planes, indicating an initial activation of slip in the (001) plane at the onset of plastic deformation. Compared to gold, the averaged uniaxial stress component in TiB2 is almost 27 times as large at the maximum loading pressure, 60 GPa, achieved in the experiment. (c) 2006 American Institute of Physics.