HR-EBSD analysis of in situ stable crack growth at the micron scale

 
9 tiles of magnified sample registering between 0.3 - 0.5 GPA

A novel approach has been developed to measure the critical conditions for cleavage crack propagation, in situ.  It uses a J-integral evaluation of the elastic energy release rate, which gives the three-dimensional stress intensity factors directly from experimental measurements of the elastic deformation gradient tensors of the crack field.

These were measured by in situ high (angular) resolution electron backscatter diffraction (HR-EBSD).  This paper in the Journal of Mechanics and Physics of Solids, by Abdo Koko with co-authors from Oxford (James Marrow, Angus Wilkinson and Elsiddig Elmukashfi), South Africa (Thorsten Becker) and Italy (Nicola Pugno), presents an exemplar study of a quasi-static crack propagating in a single crystal silicon wafer.