TENSILE TEST OF FOIL SPECIMENS OF IRON SINGLE CRYSTALS AT ROOM AND LOW TEMPERATURES UNDER OBSERVATION IN HIGH VOLTAGE ELECTRON MICROSCOPE.

Thick foil specimens of iron single crystals were stretched under observation in a 1 MV microscope at room temperature, minus 90 degree C and minus 120 degree C. The motion of individual dislocations in the stressed iron was recorded continuously and analysed in relation to the stress-strain curve of the specimen. The mobilities and densities of moving dislocations in iron at room temperature and minus 120 degree C were determined directly in this way. The results were discussed as compared with the previously reported results.