γ/γ′ interface-driven formation of imperfect twin boundaries and 9R phase in a medium-entropy superalloy

Materials Research Letters 2026 Open access

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Authors: Linfu Zhang, Ming Chen, Qiang Zhu, Yinghao Zhou, Tao Yang, Junhua Luan, Kang Liu, Jialin Xu, Debin Shan, B. Guo, Guohua Fan, Peng Zhang
DOI: 10.1080/21663831.2026.2613692
Cited by: 2
References: 35

Abstract

Medium-entropy superalloys (MESAs) show promise for extreme-temperature applications, yet their governing defect mechanisms remain unclear. Here, we reveal the hot-deformation behavior of a MESA at 1120 °C using atomic-scale characterization and molecular dynamics simulations. We observed that coherent twin boundaries (CTBs) become imperfect, forming incoherent twin boundaries (ITBs) as they propagate along γ/γ′ interfaces. These interface-driven ITBs subsequently serve as nucleation sites for a 9R phase transformation. This newly identified pathway, from interface to ITB to 9R phase, sheds new light on designing advanced superalloys with superior mechanical properties for extreme service.

Fields of Study & Subjects

High Entropy Alloys Studies High Temperature Alloys and Creep Additive Manufacturing Materials and Processes

Publication details

Journal / source
Materials Research Letters
Publisher
Informa UK Limited
Volume
14
Issue
3
Pages
295–302
Publication date
12 January 2026
Language
EN