Study on the infiltration mechanism of tellurium into the Inconel 718

• Published in: Journal of materials science Vol. 58; no. 4; pp. 1966 - 1978
• Main Authors: Li, Guoying, Liu, Zhanqiang, Wang, Bing
• Format: Journal Article
• Language: English
• Published: New York Springer US 2023; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Grain boundaries; Infiltration; Intermetallic compounds; Iron; Materials Science; Metals & Corrosion; Nickel; Nickel base alloys; Polymer Sciences; Solid Mechanics; Superalloys; Tellurides; Tellurium; Titanium
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-023-08150-x

Understanding the infiltration and destruction mechanism of element Te in the surface of nickel-based superalloys is important. The microscopic characterization of Te infiltration, elemental distribution and cracks extension in Inconel 718 were carried out. The phenomenon of Rich–Poor–Rich–Zero (R–P–R–Z) distribution of element Te, Poor–Rich–Poor–Rich (P–R–P–R) distribution of elements Cr, Ti and Nb, and Poor–Rich–Poor (P–R–P) distribution of elements Ni, Fe and Al were observed on infiltrated Inconel 718 surface. It was found that tellurides and oxides formed at grain boundaries and weak connections between tellurides and grain boundaries were jointly responsible for the grain boundary failure. The attraction of element Te and O to the metal elements inside the matrix is an important reason for the migration of elements from the matrix to the surface. The presence of oxygen is indeed a key factor in accelerating tellurium penetration into Inconel 718. Te infiltration into alloy surface was explained from the perspective of element migration generating vacancies, providing a new perspective for understanding the mechanism of Te infiltration. The root cause of grain boundary failure was clarified.