A NOTE ON GEOMETRY OF SLIP CONTROLLED BY PEIERLS MECHANISM

The macroscopic slip plane in solids with undissociated dislocations is determined as the average plane of motion of screw dislocations. It is assumed that their motion is controlled by thermally activated overcoming of the Peierls potential into different crystallographic planes. The screw dislocations have a unit motion or jump of one atomic distance and they are free to jump into a number of different positions. Under these circumstances cross slip jumps are frequent and the macroscopic slip plane for a given applied stress is determined by the Peierls potential in the different planes of cross slip. The geometry of slip in b.c.c. metals is discussed in some detail and it is shown that experimental results can be described formally using this approach. © 1969 Academia, nakladatelství Československé akademie věd.