DETERMINATION OF X-RAY ELASTIC-CONSTANTS USING AN IN-SITU PRESSING DEVICE

The experimental determination of x-ray elastic constants are performe d by in sial measurements of the dependence of the strain state in sel ected crystallites for different applied external compressive stresses . The use of compressive applied stresses instead of tensile applied s tresses is of interest for x-ray elastic constant determinations for m aterials which exhibit brittle crack-like behavior, which cannot be lo aded to high tensile stresses in, for example, four-point bending devi ces. The x-ray elastic constants for {146} alpha-Al2O3 are determined with the pressing device and compared to calculated as well as experim entally determined values which were tested in tensile loading devices .