Mechanical properties and fracture characteristics of a typical hard-to-deform superalloy GH4079 prepared by powder metallurgy technology

作者：Bing Sun, Jiaming Bai, Cheng Luo, Kang Lu, Zonghong Qu, Zhigang Zhang, Jiaming Song, Qingxiang Wang, Tiebang Zhang, Yunjin Lai, Shaoqiang Li · 发表于：Journal of Materials Research and Technology · 年份：2025 · DOI：10.1016/j.jmrt.2025.11.030 · 被引用次数：5 · 研究领域：Additive Manufacturing Materials and Processes、Metallurgy and Material Forming、High Temperature Alloys and Creep

For the typical hard-to-deform superalloy GH4079, traditional deformation processes including forging and ring rolling are highly prone to problems including cracking, abnormal grain growth during the subsequent heat treatment, and anisotropic distribution of mechanical properties. Hence, the supreme speed plasma rotating electrode process (SS-PREP®) is employed to prepare high-quality, spherical alloy powder particles. Subsequently, the GH4079 billet has been produced by combining the powder metallurgy (PM) processing with heat treatment. Results demonstrate that the microstructure of PM GH4079 is characterized by uniform equiaxed grains, with carbides distributed uniformly. In addition, the impact fracture surface exhibits both dimples and cleavage steps, indicating a mixed ductile-brittle fracture mechanism. Furthermore, the alloy's ultimate tensile strength and yield strength at room temperature reach 1536 ± 5 MPa, and 1055 ± 4 MPa, respectively. Moreover, its stress-rupture life under the condition of 650 °C/882 MPa can exceed 210 h. Evidently, its mechanical properties are considerably superior to the current technical specifications for forged components. The successful implementation of this innovative process not only solves the issues related to the deformation and mechanical properties of hard-to-deform superalloys but also expands the application scope of the powder metallurgy technology.