MORPHOLOGY OF DEFORMED ZONE OF MICRO- AND NANOINDENTATION ON CRYSTALS WITH DIFFERENT TYPE OF BOND

The comparison of microindentation (MI) and nanoindentation (NI) methods has been made. Differences between nanohardness (Hn) and microhardness(Hm) values were found. The deformation zone around these two types of indentations, the dislocation structure and the thin structure of indentation relief have their specific peculiarities, which were attributed to the scale effect and different deformation extent of material under MI and NI. 2. Experimental technique A wide range of crystals KCl, LiF, MgO, CaF2, GaP, Si with different type of bond, from typically ionic to typically covalent, was chosen for investigation. This choice was stipulated for comparison and generalization of obtained results. Indentations were made on (001) plane for KCl, LiF, MgO, GaP crystals and (111) planes for CaF2 and Si, using the Nano Indenter II (MTS Systems, USA) with diamond trihedral Bercovich pyramid as indenter and loads Pmax = (0.01÷0.12)N, and Microindenter PMT-3 with diamond tetrahedral Vickers pyramid as indenter and loads P = (0.01÷2.0)N. Nanohardness was determined using the standard method described in (2), microhardness was determined from the known formulae H = 1,854 P/d 2 , where d - is the indentation diagonal. The thin structure of surface relief of indentations was investigated using Atomic-force microscope (AFM) (trademark Nanostation) and the dislocation zones around the indentations were revealed using etch-pit technique.