INFLUENCE OF ELECTRO DISCHARGE MACHINING ON THE MOSAICITY OF A BERYLLIUM SINGLE-CRYSTAL

The plastic deformation of a beryllium single crystal by electro discharge machining was examined by γ-ray diffraction and X-ray topography to study the gradient of the mosaic distribution from the surface into the bulk of the crystal as a function of the intensity of the current and the crystal orientation. An enlargement of the mosaicity up to 0.2° with increasing intensity of the current has been found for cutting the crystals parallel to the basal plane. This effect is in practice limited to a depth of 0.1 mm. © 1990.