Evolution of orientation distributions of γ and γ′ phases during creep deformation of Ni-base single crystal superalloys

✍ Scribed by Toru Inoue; Katsushi Tanaka; Hiroki Adachi; Kyosuke Kishida; Norihiko L. Okamoto; Haruyuki Inui; Tadaharu Yokokawa; Hiroshi Harada

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 355 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.10.042

✦ Synopsis

The evolution of orientation distributions of c and c 0 phases in crept Ni-base single crystal superalloys have been investigated by theoretical calculations with elastic-plastic models and by experiments. As creep deformation proceeds, the crystallographic orientation distributions for both phases are broadened as a result of the waving of the raft structure, which occurs to reduce the total mechanical energy. The broadening of the orientation distribution occurs in such a way that the 0 0 1 pole broadens isotropically while the h k 0 poles broaden preferentially along the h0 0 1i directions. Since the extent of the broadening increases almost linearly with the number of creep deformation, the measurement of the broadening by X-ray diffraction can be utilized in non-destructive methods to predict the lifetime of Ni-base superalloys.