Creep damage

Creep damage by void nucleation and growth limits the lifetime of components subjected to loading at high temperatures. In order to better understand the process Pyzalla et al. performed combined tomography and energy dispersive diffraction measurements using high-energy synchrotron radiation that permitted to follow in situ void growth and microstructure development in bulk samples. The experiment revealed that void growth kinetics during creep could be studied in the bulk material in situ. The 3D bulk information further provided access to a quantitative determination of void size and void shape evolution during creep. This comprehensive 3D representation of creep damage in the sample confirmed the proposition that the transition from homogeneous to localized creep damage occurs late in creep life. The results revealed that void growth versus time follows an exponential growth law.

Pyzalla A., Camin D., Buslaps T., Di Michiel M., Kaminski H., Kottar A., Pernack A., Reimers W. - Simultaneous tomography and diffraction analysis of creep damage - Science 308, 92-95 (2005)

Slice of the brass alloy, CuZn40Pb2, after 348min creep (top) and 431min creep (bottom).