X-Ray Stress Measurement of Nickel-Base Single Crystal Superalloy Using Two-Dimensional PSPC
Shutarou MACHIYA, Keisuke TANAKA and Yoshiaki AKINIWA
Abstract:The stress in a single crystal of nickel-base superalloy with 72% volume fraction of ƒÁ'-phase was measured by the X-ray method. The specimen whose surface normal was parallel to [001] direction was oscillated around ƒÓ-axis during recording of the X-ray diffraction pattern with a two-dimensional position sensitive proportional counter (PSPC). The stress was determined from the measured strain using the multiple regression method and the two-tilt method. The uniaxial stress was applied along [100] direction and the stresses were measured with the X-ray methods. The stress along [100] direction, ƒÐ11, measured with the X-ray method increased proportionally to the applied uniaxial stress, and the measured stress was about 5 % smaller than the applied stress. The other stress components, ƒÐ22 and ƒÐ12, did not change with the applied stress. With respect to the machined surface, the residual stress was a compression of about 700 MPa on the surface and abruptly decreased to zero at about 15ƒÊm beneath the surface. The increase in the full-width at half maximum was observed within the depth of about 15ƒÊm from the machined surface. Key Words:X-ray stress measurement, Single crystal, Nickel-base superalloy, Residual stress distribution, Full-width at half maximum