The coefficients of the strain-rate sensitivity of plastic characteristics (including microhardness) carry useful information concerning the nature of elementary carriers of plastic deformation and their mobility in a solid. In macrotests of various ductile materials (see, e.g., [1]), a wide range of strain rates ε (between 10~(-8) and 10~6 s~(-1)) was investigated. However, fracture of many brittle materials (in particular, single crystals with covalent bonds, ceramics, glasses, etc.) begins before noticeable plastic strain. The plastic properties of such materials are usually studied by the methods of local deformation or microindentation. In recent years, the method of nanoindentation has also been extensively used in this field [2-4]. Famous firms (MTS, Micromaterials, CSEM, Hysitron, etc.) produce commercial nanotesters only for small ε values (10~(-3) - 10~(-1)s~(-1)). At the same time, very high rates of local deformation in submicron areas (10~(-1) s~(-1)) are characteristic for many processes, including dry friction between rough surfaces, abrasive and erosive wear, atomic-force microscopy, nanolithography by the methods of imprinting and scribing, and fine grinding [5]. Thus, the area of the mechanical properties of materials that is characterized by both short loading time intervals and small deformation zones is little studied. Under these conditions, the ordinary mechanisms (in particular, dislocation mechanisms) of plastic flow can be strongly impeded or suppressed.
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