Crystal perfection studies of single crystal superalloy turbine blades by X-ray diffraction methods

In the paper the crystal structure of single crystal CMSX-4 blade casts, applied in high pressure turbine of aircraft engines was analyzed. The longitudinal section of blade, cast at withdrawal rate of 3 mm/min was used as a sample. During the conducted research, following X-ray diffraction methods were applied: EFG Ω-scan, Auleytner X-ray topography and analysis of diffraction reflex profile ("rocking curve"). The authors determined crystal orientation in entire blade casts on the basis of set criterion concerning values of angle α - deviation of [001] direction from the direction of cast withdrawal. Conclusions concerning the crystal structure quality of the blade were drawn based on results from three different research methods. Local changes in crystal orientation on the surface of blade cast, also areas with significant structure defect degree and the presence of internal stresses were characterized.