STUDY OF CREEP DEFORMATION OF NI_3GE SINGLE CRYSTALS WITH 234 AND 122 ORIENTATIONS

摘要

The creep properties of the Ni_3Ge alloy with [ 234] and [ T22] orientations were investigated by tests under constant-load at three different elevated temperatures 873, 923, 973K exceeding the temperature of the stress peak (T_p) and different compressive stresses. The examined crystals demonstrate two-stage creep curves. There is the primary stage where the strain rate decreases and the secondary one stays steady. Creep rates show normal temperature dependence, the creep rates increase _with the increasing of temperature. The single crystals of the Ni_3Ge alloy with [ 234] and [ 122] orientations display high stability to changing temperature. The creep rates weakly depend on temperature.