Effect of Ti content on creep properties of Ni-base single crystal superalloys

• Published in: Metals and materials international Vol. 23; no. 5; pp. 877 - 883
• Main Authors: Choi, Baig Gyu, Kim, In Soo, Hong, Hyun Uk, Do, Jeonghyeon, Jung, Joong Eun, Jo, Chang Yong
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.09.2017; Springer Nature B.V; 대한금속·재료학회
• Subjects: Alloys; Antiphase boundaries; Characterization and Evaluation of Materials; Chemistry and Materials Science; Creep (materials); Creep life; Creep strength; Creep tests; Crystal defects; Cutting parameters; Deformation effects; Deformation mechanisms; Deformation resistance; Dislocations; Engineering Thermodynamics; Heat and Mass Transfer; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Nickel base alloys; Photomicrographs; Processes; Single crystals; Solid Mechanics; Superalloys; Transition temperature; Transmission electron microscopy; 재료공학; transmission electron microscopy (TEM); creep; alloys; casting; Ni-based superalloy
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-017-7089-7

The effect of Ti content on the creep properties and microstructures of experimental Ni-base single crystal superalloys has been investigated. The experimental alloys were designed to provide better high temperature properties than the commercial single crystal alloy CMSX-4. The creep properties of the experimental alloys, Alloy 2 and Alloy 3, were superior to those of CMSX-4. Alloy 3 showed a longer creep life than Alloy 2 at 900 °C and 950 °C, while it has similar creep life with Alloy 2 at 982 °C. Transmission electron microscopy micrographs of the experimental alloys after the creep test showed distinct deformation features as a function of temperature and Ti content. The dissociation of dislocations into partial dislocations with stacking faults in Alloy 3 was found to improve resistance to creep deformation at 950 °C. The effect of Ti on the creep deformation mechanism was not evident at 982 °C, which resulted in similar creep properties in both experimental alloys. The transition of the γ′ cutting mechanism from dislocations coupled with stacking faults to anti-phase boundary coupled pairs occurred both in Alloy 2 and Alloy 3. However, the transition temperature was higher in Alloy 3 than in Alloy 2 because of the difference in Ti contents.