| Autor: |
Qiao, Jingbo, Zhang, Hongmin, Meng, Haoyan, Meng, Fanchao, Tong, Yang, Chao, Daiyi, Liaw, Peter K., Chen, Shuying |
| Zdroj: |
Metals & Materials International; Feb2024, Vol. 30 Issue 2, p380-392, 13p |
| Abstrakt: |
The equiatomic high entropy alloy (HEA) NiCoCrFePd crystalizes as a single face-centered cubic (FCC) phase with strong local lattice distortion due to large atomic size mismatch between Pd element and other constitute elements. To better understand this quinary alloy, a family of single FCC phase equiatomic alloys made from the constituent elements of the NiCoCrFePd HEA, including the binary NiPd alloy, medium entropy alloys (MEAs) of NiCoPd, NiCrPd, and NiFePd, and the quinary NiCoCrFePd HEA with fully-recrystallized microstructure was experimentally investigated to understand the chemical effects on grain growth kinetics and solid solution hardening. With the principal elements increasing from two to five, the grain growth was increasingly inhibited in the annealing temperature range of 800–900 °C, while at 1000 °C and above, the NiCrPd MEA showed the slowest grain growth, which may attribute to the higher melting temperature of Cr and negative mixing enthalpy between Cr and other constituent elements, increasing the activation energy of grain growth. Moreover, the hardness depending on the grain size complied with the Hall-Petch relationship, in which NiCoPd exhibited the lowest hardness, while NiPd had a comparable hardness with NiCrPd and NiFePd. The above results suggested that the number of alloying elements was not the sole factor determining the sluggish diffusion and hardness. Instead, the type of constituent elements in the Pd-containing multicomponent alloys played more critical role. Furthermore, it was concluded that the strength of MEAs and HEA should depend on the combination of atomic size and modulus mismatch and electronegativity difference. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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