The influence of the mode of hardness increase on the dislocation mobility of the crystal with NaCl lattice

Abstract

Abstract The influence of the three types of hardening (1 – radiation hardening; 2 – the hardening in lowering of temperature; 3 – the hardening in the series of KCl‐NaCl‐NaF‐LiF‐MgO crystals) on the length of dislocation rosettes arms is investigated. This length characterizes the dislocation ensemble mobility in the nonuniform stress field. It is shown that the change of microhardness and that of mobility of dislocations correlate well while introducing the radiation damage. In contrast to it the microhardness rise does not cause marked decrease of the length of rosettes arms in the other two cases. The conclusion is made that the length of rosettes arms depends not only upon the value of crystal hardness but also upon the mode of origin of this value. On the (001) plane of the crystals under investigation it is found that the length of dislocation rosettes arms depends on the indentor orientation. A possible explanation of this phenomenon is proposed.