Deformation of alkali-metal halide crystals by a concentrated load

The parameters characterizing the effect of a concentrated load on crystals subjected to various preliminary treatments and their possible relationship to the mechanical characteristics manifested during ordinary (one-dimensional) deformation are investigated. The significant upward deviation of the microhardness from the values of the elastic limit and yield strength of crystals is shown to be caused not so much by the larger values of the strain under an indenter as by the larger value of the strain hardening coefficient in the case of deformation by a concentrated load. It is also shown that the types of hardening caused by uniaxial deformation and by reactor irradiation influence the microhardness of LiF crystals differently. Fiz. Tverd. Tela (St. Petersburg) 41, 1999–2003 (November 1999)