WHITE BEAM SYNCHROTRON TOPOGRAPHY AND GAMMA-RAY DIFFRACTOMETRY CHARACTERIZATION OF THE CRYSTALLINE QUALITY OF SINGLE-GRAIN SUPERALLOYS - INFLUENCE OF THE SOLIDIFICATION CONDITIONS

The industrial success of manufacturing single-grain superalloy turbin e blades is linked to a good control of the crystalline quality of the material, which depends strongly on the solidification conditions. Us ing gamma-ray diffractometry and white beam x-ray topography we study the influence of the value of the thermal gradient at the solidificati on front and at the rate of growth on the mosaic spread of the grain. The different contributions to the mosaic spread of superalloys are po inted out, as well as the relations with dendrite arrangements.