| Popis: |
We studied microstructure changes of a Nickel-based super-alloy (Waspaloy) subjected to a tensile stress at 1073 K. We monitored the shear-wave attenuation and velocity using electromagnetic acoustic resonance (EMAR) The attenuation peaks 35% and 40% of creep life, being independent of applied stress. A drastic change in dislocation mobility and arrangement interrupted this novel attenuation phenomenon, as supported by SEM and TEM observation. The relationship between attenuation change and microstructural evolution can be explained with the string's model. EMAR demonstrates a potential for assessing damage advance and predicting the remaining creep life of metals. |
