Coarsening behavior of γ′ and γ″ phases in GH4169 superalloy by electric field treatment

• Published in: International journal of minerals, metallurgy and materials Vol. 20; no. 9; pp. 861 - 866
• Main Authors: Wang, Lei, Wang, Yao, Liu, Yang, Song, Xiu, Lü, Xu-dong, Zhang, Bei-jiang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2013; Springer Nature B.V; Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang 110819, China%Department of High-temperature Materials, Central Iron and Steel Research Institute, Beijing 100081, China
• Subjects: Aluminum; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Clusters; Composites; Corrosion and Coatings; Diffusion coefficient; EFT; Electric fields; Gamma-double prime phase (crystals); GH4169合金; GH4169高温合金; Glass; Materials Science; Metallic Materials; Natural Materials; Nickel base alloys; PALS; Phases; Positron annihilation; Strain energy; Superalloys; Surfaces and Interfaces; Thin Films; Tribology; 正电子湮没寿命谱; 电场处理; 粗化行为; 透射电子显微镜; precipitation; vacancies; electric fields; nickel alloys; aging; superalloys
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-013-0807-3

The coarsening behaviors of γ′ and γ″ phases in GH4169 alloy aged at 1023 and 1073 K with electric field treatment （EFT） were investigated by transmission electron microscopy （TEM） and positron annihilation lifetime spectroscopy （PALS）. It is demonstrated that precipitation coarsening occurs, and the growth activation energies of γ′ and γ″phases can be decreased to 115.6 and 198.1 kJ.mo1-1, respectively, by applying the electric field. The formation of a large number of vacancies in the matrix is induced by EFT. Due to the occurrence of vacancy migration, the diffusion coefficients of A1 and Nb atoms are increased to be 1.6-5.0 times larger than those without EFT at 1023 or 1073 K. Furthermore, the formation of vacancy clusters is promoted by EFT, and the increase in strain energy for the coarsening of γ′ and γ″ phases can be counterbalanced by the formation of vacancy clusters.