Slip on {110} in 〈001〉 Nb single crystals deformed in compression at 77°K

Abstract

Single crystals of niobium were deformed in compression along 〈001〉 at 77°K to a few percent strain at several strain rates. The nature of the deformation was examined by optical, replica, scanning and transmission microscopy. With the exception of the impact-loaded specimen the deformation occurred by highly regular {110}〈111〉 slip on the four equi-stressed systems. Transmission electron microscopy has confirmed that the anomalous 〈110〉 surface offset observed is due to the simultaneous operation of the two ½ 〈111〉 dislocations on the appropriate {110} planes.