Stress cycle testing during creep of a particle-strengthened Nb-1Zr-0.1C alloy

Stress cycle testing was performed during high-temperature creep of a particle-strengthened alloy of niobium (Nb-1Zr-0.1C). Two methods were used to analyze the data from the stress cycles to determine the back stress arising from the dislocation substructure as a function of applied stress, temperature, and accumulated strain. Back stresses as high as 96% of the applied stress were measured. In general, the normalized effective stress, calculated from the dislocation back stress, was shown to be independent of the applied stress and temperature.