It was noted that the physical mechanisms, which were involved in the formation of the deformation zone near to an indentation, remained unclear because of inadequate data on the dynamics of the material structure beneath an indenter during its use. The available information on the size of the dislocation rosette and its structure applied only to long indentation times (tens or hundreds of seconds), and there were almost no data on shorter indentation times; during which the most of the indentation formed. It was shown that indentation formation during the micro-indentation of ionic crystals having a NaCl-type lattice took place in several distinct stages which lasted from a few ms to tens of seconds. They were distinguished by their characteristic times, kinetics, activation parameters and micro-mechanisms of mass transport in the contact zone. It was thus expected that the deformation zone might have differing structures and dynamics in each stage.

Dynamics of Imprint and Dislocation Rosette Formation by Pulsed Micro-Indentation of Ionic Crystals. J.I.Golovin, V.I.Ivolgin, V.V.Korenkov, A.I.Tyurin: Fizika Tverdogo Tela, 1997, 39[2], 318-19 (Physics of the Solid State, 1997, 39[2], 278-9)