Creep deformation of a sixth generation Ni-base single crystal superalloy at 800°C

• Published in: Materials Science and Engineering: A Vol. 608; pp. 95 - 100
• Main Authors: Yuan, Y., Kawagishi, K., Koizumi, Y., Kobayashi, T., Yokokawa, T., Harada, H.
• Format: Journal Article
• Language: English; Japanese
• Published: Kidlington Elsevier B.V 01.07.2014; Elsevier BV; Elsevier
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Creep; Creep mechanism; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Deformation, plasticity, and creep; Exact sciences and technology; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Ni-base superalloy; Physics; Single crystal; Sixth generation; Stacking fault energy; Stacking faults and other planar or extended defects; Structure of solids and liquids; crystallography; Treatment of materials and its effects on microstructure and properties; Creep mechanism; Stacking fault energy; Sixth generation; Ni-base superalloy; Single crystal; Shear; Creep; Creep test; Stacking fault; Precipitate; Superalloy; Rhenium addition; Microstructure; Creep deformation
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2014.04.069

The interrupted creep tests (ε=0.1%) of a fourth and a sixth generation Ni-base single crystals, i.e. MX-4/PWA 1497 and TMS-238, were conducted at 800°C and 735MPa along [001]. TMS-238 had a creep time more than sixty times longer than MX-4/PWA 1497. Microstructural observations showed that stacking faults (SFs) sheared both the γ matrix and γ΄ precipitates in MX-4/PWA 1497, however, SFs sheared only the γ matrix in TMS-238. The factors that affect the creep deformation are discussed. The results imply that the stacking fault energy (SFE) of γ matrix in TMS-238 is lower than that in MX-4. Higher additions of Re and Ru are responsible for the lower SFE in TMS-238.