Translation–rotation plasticity as basic mechanism of plastic deformation in macro-, micro- and nanoindentation processes

Abstract

This paper presents a brief review of multilateral examinations for the purpose of detection of interrelation between processes occuring in solids at different levels of action of exterior loading, namely, at macro-, micro- and nanoindentation. Convincing arguments supporting the rotation deformation mechanism alongside the recognized dislocation one are adduced. It has been shown that the decrease in dislocation mobility leads at all scales to the intensification of rotation plasticity and to the involvement of other plastic deformation mechanisms, such as appearance and interaction of disclinations, twinning, phase transition and compression of material. The conversion from translation plasticity to the rotation–translation one means transition to the higher level of plastic deformation, the mesolevel, when the possibilities of the previous microscopic level are exhausted. It was established that the plastic deformation zone in the vicinity of indentations could be separated into two main specific regions: (i) peripheral region predominantly with the dislocation deformation mechanism; otherwise, translation mechanism: microlevel, and (ii) quasidestructured region mainly with the disclination or the intergranular sliding mechanism: rotation mechanism, mesolevel.

Indentation Hardness Measurements at Macro-, Micro-, and Nanoscale: A Critical Overview

“…There are just very few studies comparing the indentation hardness of materials at the three scales. Grabco et al [6] studied crystals with different types of bonds (ionic, ionic-covalent, covalent, covalent with some sharing Van der Waals bond, and metal bonds) in the form of single crystals and polycrystals. They used nanoindentation with a Berkovich indenter at loads in the range 0-0.2 N, micro-indentation with Vickers diamond indenter in the range 0.01-2 N, and macroindentation with a steel ball at loads [10 N. Rester et al investigated the hardness of copper {111} single crystals, with indentation depths ranging from 250 to 250 lm [58].…”

“…The transition from macroscale to microscale and from microscale to nanoscale indentation hardness measurement is accompanied by a decreasing influence of some of these factors and by an increasing contribution of others [6]. Indentation hardness value also depends on the test used to measure it.…”

Indentation Size Effect and the Hall-Petch ‘Law’

“…The notion that there is a transition from laminar to rotational flow under an indenter is certainly not new: a summary of related work from the Moldovian Academy of Sciences [29] indicates that the rotation mechanism has for some years been viewed as a disclination process, operating at the mesolevel, in contrast to the dislocation (laminar) process at the microlevel. Also the view of Chaudhri [4] that flow occurs first into the material and then upwards towards the surface is well established, particularly for ceramics like MgO.…”

Чувствительность дислокационных розеток к форме индентора Берковича на кристаллах LiF и MgO

“…Механизм деформации материалов при индентировании интенсивно исследуется в научной литературе на протяжении уже нескольких десятилетий [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Во-первых, это связано с тем, что метод индентирования приобрел характер универсального способа для оценки механических свойств различных материалов: твердости, прочности, упругости, пластичности, хрупкости [3,4,18,19].…”