A general-purpose mechanical testing device was tested for the purpose of in situ experiments using synchrotron radiation. A new set-up was used to investigate the reversibility of dislocation motion under stress reversal. The observations were performed by in situ transmission X-ray topography. Specimens of float-zone single crystals, with a [1¯14] axis (double slip orientation), were submitted to load cycles in tension and compression (τ = 10 to 20MPa) at 650 to 750C. Dislocations were created at the surfaces by Vickers indentations. They were observed using a monochromatic beam (λ = 0.035nm) and a 220 diffraction vector. The observations showed that dislocations could behave in different ways within the same specimen, and that their motion could be partially reversible.

Mechanical Testing Device for in situ Experiments on Reversibility of Dislocation Motion in Silicon. J.P.Feiereisen, O.Ferry, A.Jacques, A.George: Nuclear Instruments and Methods in Physics Research B, 2003, 200, 339-45