Slip systems in NiAl single crystals at 300°K and 77°K

Abstract

Abstract Single crystals of NiAl have been examined by transmission electron microscopy after plastic deformation at 300°K and 77°K. In agreement with earlier work, it is found that single crystals generally slip along 〈100〉. Further, it is shown that crystals oriented so that there is zero applied stress on the dislocations of b = 〈100〉, deform by the movement of dislocations of b = 〈111〉 on {112} and {110}. A lower limit to the Peierls stress for dislocations of b = 〈111〉 is calculated from the observed spacing of opposite sign screw dislocations, and it is shown that these dislocations are far more difficult to move than mobility calculations would suggest.