Comparing Techniques for Quantification of Creep Cavities

Creep cavitation is a key limitation for the life of a component acting under load at elevated temperatures. This paper compares several modern techniques available to characterize and understand the formation of creep cavities. Conventional 2D imaging techniques such as Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) imaging characterize morphology and distribution over a large area, while scanning transmission electron microscopy (STEM) has higher resolution but limited sampling area. 3D imaging techniques such as X-ray Tomography (XRT) enable the characterization of creep cavities in three dimensions, however XRT can be limited in cavity identification due to resolution. To bridge the length-scale gap, FIB serial sectioning can reconstruct the creep cavities at a single grain boundary with a much higher resolution, whilst advancements in Plasma FIB enable this high resolution characterization over a larger reconstruction volume. For optimum creep cavitation characterization, multiple techniques should be used in complement with each other.