‘Microstrain’ in neutron irradiated copper crystals

Publisher Website
Google Scholar
Abstract
It has been shown by a sensitive parallel plate condenser technique that no deformation (> 1 × 10−6 strain) occurs in neutron irradiated (2.5 × 1018 f. n. cm−2) copper single crystals at stresses lower than the ‘critical’ shear stress at the appropriate strain rate. When the critical stress is reached the deformation occurs entirely by the formation of prominent slip lines, there being no sign of fine slip, viz. the limited movement of dislocations on a large number of slip planes. This result supports the model of slip in neutron irradiated metals proposed by Makin and Sharp and is contrary to the large microstrain observed by Koppenaal in bend tests.