Effects of initial microstructures on serrated flow features and fracture mechanisms of a nickel-based superalloy
| Autor: | Yunchang Xin, Hui Yang, Yong-Cheng Lin, Chang-Zheng Li |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Mechanical Engineering Nucleation chemistry.chemical_element 02 engineering and technology Slip (materials science) 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Carbide Superalloy Nickel chemistry Mechanics of Materials 0103 physical sciences General Materials Science Deformation (engineering) Composite material Elongation 0210 nano-technology |
| Zdroj: | Materials Characterization. 144:9-21 |
| ISSN: | 1044-5803 |
| DOI: | 10.1016/j.matchar.2018.06.029 |
| Popis: | The uniaxial tensile experiments are performed on a nickel-based superalloy with different initial microstructures at intermediate temperatures (473–973) K and low strain rates (0.0001–0.001) s−1. Effects of initial microstructures on plastic deformation mechanisms, serrated flow features, and fracture characteristics are analyzed. It is clearly demonstrated that the plastic deformation mechanism of serrated flow is irrelevant to the initial microstructures, and the dislocation across slip in the matrix is responsible for the serrated flow. However, the effects of initial microstructures on fracture mechanisms are obvious, i.e., the main fracture mechanism of the ST (solution treated) and HS (solution plus γ′/γ″ phases aging precipitation) superalloys are the nucleation and growth of micro-voids, which accelerates the break of carbides and interfacial failure of carbides/matrix. While for the SAT (solution plus δ phases aging precipitation) superalloy, δ phases and carbides play a significant role in the nucleation of micro-voids. Furthermore, the increase of the deformation temperature reduces the elongation to fracture of the ST and HS superalloys. However, the better tensile ductility is obtained with raising the deformation temperatures for the SAT superalloy. |
| Databáze: | OpenAIRE |
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