The Effect of Aging Treatment Temperature on Microstructure and Stress-Rupture Properties of a Fourth Generation Ni-Based Single Crystal Superalloy(PDF)
MATERIALS CHINA[ISSN:1674-3962/CN:61-1473/TG]
Issue:
2025年06
Page:
561-567
Research Field:
Publishing date:
Info
Title:
The Effect of Aging Treatment Temperature on Microstructure and Stress-Rupture Properties of a Fourth Generation Ni-Based Single Crystal Superalloy
Science and Technology on Advanced High Temperature Structural Materials laboratory, Beijing Institute of Aeronautical Materials, Beijing 100095, China
To investigate the influence of primary aging temperature on the microstructure and stress-rupture properties of a fourth-generation Ni-based single-crystal superalloy, high-resolution field emission scanning electron microscopy and optical microscopy were employed to characterize microstructural evolution during heat treatment, high-temperature stressrupture fracture morphology and microstructure of cross-sections. The results revealed that solution treatment effectively eliminated (γ+γ′) eutectic structures and substantially reduced elemental segregation. Primary aging modified γ′ precipitate size and morphology, where increasing temperature promoted γ′ coarsening in dendritic areas, diminished cuboidal integrity and widened γ matrix channels. Consequently, elevated primary aging temperatures reduced the stress-rupture life at 1120 ℃/137 MPa. The stressrupture performance exhibited critical dependence on γ′ precipitate morphology, size, volume fraction and γ channel width. Optimally sized, highly cuboidal γ′ precipitates strongly impeded dislocation motion, while the Orowan stress for dislocation glide within γ channels demonstrated inverse proportionality to channel width. Comprehensive evaluation established 1140 ℃ as the optimal primary aging temperature for this alloy.