| Autor: |
Zhang, Weiwei, Tan, Yuanguo, Tariq, Naeem ul Haq, Si, Tianxiao, Wang, Zhiyuan, Xin, Xin, Sun, Wenru |
| Předmět: |
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| Zdroj: |
Journal of Materials Engineering & Performance; Apr2023, Vol. 32 Issue 8, p3420-3430, 11p |
| Abstrakt: |
Laves phases are regarded as topologically close pack phases in superalloys, which damage mechanical properties, especially notch sensitivity of the material. However, here we innovatively found that the formation of large blocky primary Laves phase in Thermo-Span alloys does not cause notch sensitivity. The influence of primary Laves phases on the notch sensitivity was investigated via electron backscattered diffraction, transmission electron microscopy, and scanning electron microscopy. We found that primary Laves phases eliminate the notch sensitivity through inhibition of γ′ phase precipitation. The reduction of γ′ phases resulted in a decrease in grain-interior strength along with improvement in plasticity, thereby promoting the occurrence of intragranular plastic deformation. The intragranular plastic deformation can coordinate with incompatible deformation among neighboring grains, and thus crack initiation and propagation at grain boundaries was inhibited. These findings provide a new understanding of Laves phases; more importantly, providing a way to improve/eliminate the notch sensitivity of the alloy. Moreover, Abaqus software was employed to assess the stress distribution at different parts of combined-stress rupture samples. It was revealed that the difference in stress distribution at the notched and smooth regions is the main reason associated with different fracture locations for the samples with different resistance to crack initiation and propagation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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