Journal Article

Study on Dislocation Decomposition Mechanisms and Crack Propagation Modes in a Re/Ru Single-Crystal Nickel-Based Alloy During Room-Temperature Tensile Testing

Zhang, Shunke, Shang, Xiaojuan, Xie, Zhiying, Wang, Liyuan, Qu, Xingda, Sun, Shulei, Tian, Ning, Dang, Danping

2026

Overview

Through room-temperature tensile testing, microstructural observation, and comparative analysis of dislocation configurations, this study investigates the deformation and damage behavior of a high-concentration Re/Ru single-crystal alloy. The results show that the alloy possesses excellent mechanical properties at room temperature, with a tensile strength of 875 MPa and a yield strength of 847 MPa. During tensile deformation, plastic strain primarily occurs through dislocation slip within the γ matrix and dislocation shear into the γ′ phase. Dislocations sheared into the γ′ phase exhibit distinct decomposition patterns. Microcracks initiate at γ′/γ interfaces where two slip systems intersect. As tensile loading continues, these microcracks coalesce, leading to increased local stress and unstable crack propagation along the γ/γ′ interfaces, ultimately resulting in fracture. This process constitutes the deformation and damage mechanism of the alloy during room-temperature tensile deformation. These findings suggest that high Re/Ru concentrations fundamentally alter low-temperature deformation pathways, which may improve resistance to brittle fracture during cold start or handling conditions.

• Publisher: MDPI AG
• Subject: Aircraft / Airplane engines / Alloys / Cooling / Crack propagation / Damage assessment / damage characteristics / Decomposition / Deformation / deformation characteristics / Directional solidification / Dislocations / Gamma-prime phase (crystals) / Low temperature / Mechanical properties / Microcracks / microstructure / Nickel alloys / Nickel base alloys / Plastic deformation / Propagation modes / Room temperature / Scanning electron microscopy / single crystal superalloy / Single crystals / Stress propagation / Superalloys / Temperature / Tensile deformation / Tensile strength / Tensile tests / Turbines / ultimate tensile strength / Yield stress