THE EFFECT OF TEMPERATURE AND THE DEFORMATION MODE ON THE PROPERTIES OF ZnGa 0,2 AT% SINGLE CRYSTALS WPLYW TEMPERATURY I SPOSOBU ODKSZTALCENIA NA WLASNOSCI MONOKRYSZTALOW ZnGa 0,2%AT

摘要

ZnGa0.2at.% single crystals, prestrained in thesystems (0001) <1120> and {1122} <1123>, and next subjectedto deformation in the system (0001) <1120> at the strain ratesε1=7×10-4s-1 and ε2=7×10-3s-1, were investigated in acompression test at t he temperatures 77, 295 and 473 K. Not –prestrained single crystals were examined for the purpose of comparison.It has been found that in both examined systems prestrainingcauses an increase of shear stresses in the system (0001)<1120> at the temperatures 77K and 295K, and a decrease at thetemperature 473K at prestraining in the basal system. A complexcharacter of the influence of temperature and of the change in thedeformation path on the strain rate sensitivity and the activatedvolume has been observed. Structural observations have revealedthat the boundaries of subgrains affect the process of strainhardening and the formation of shear bands.