Zhirui Yao
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
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Zhirui Yao has a total of 4 co-authors. Here are the top co-authors by number of shared publications:
- Hanxin He
School of Civil Engineering, Xi’an University of Architecture and Technology, No. 13 Yanta Road, Xi’an 710055, China
2 shared publications - Junfeng Xu
School of Materials and Chemical Engineering, Xi’an Technological University, Xi’an 710021, China
2 shared publications - Xuyang Li
Xi’an Institute of Optics and Precision Mechanics, Xi’an 710119, China
2 shared publications - Xianzhe Shi
Aerospace College, Northwestern Polytechnical University, Xi’an 710021, China
1 shared publication
Latest Publications
- Open Access
Microstructure Evolution of Rapid Solidified Invar Alloy
Invar alloy has a wide range of applications in aerospace and precision instruments. However, the microstructure evolution during rapid solidification is not yet fully understood. In this study, the rapid solidification microstructure of Invar alloy with undercooling ranging from 5 K to 231 K was investigated using optical microscopy, EBSD, and TEM techniques. The results show that, as the undercooling increased from 5 K to 181 K, the microstructure transitioned from large dendrites to columnar grains and finally to small equiaxed grains. When the undercooling ranged from 181 K to 193 K, the grain size suddenly increased before continuing to decrease with further undercooling. EBSD analysis revealed that, for ΔT > 181 K, two distinct types of grains appeared in the microstructure: one larger and the other much smaller. Under low undercooling conditions, the grains grew anisotropically with a preferred orientation, while under high undercooling, there was no apparent preferred growth orientation. Many twin boundaries were observed in the high-undercooling samples, which were further confirmed by TEM analysis. Additionally, both twin boundaries and high-angle grain boundaries increased gradually with undercooling.
Open AccessMicrostructure Evolution of Rapid Solidified Invar Alloy
Invar alloy has a wide range of applications in aerospace and precision instruments. However, the microstructure evolution during rapid solidification is not yet fully understood. In this study, the rapid solidification microstructure of Invar alloy with undercooling ranging from 5 K to 231 K was investigated using optical microscopy, EBSD, and TEM techniques. The results show that, as the undercooling increased from 5 K to 181 K, the microstructure transitioned from large dendrites to columnar grains and finally to small equiaxed grains. When the undercooling ranged from 181 K to 193 K, the grain size suddenly increased before continuing to decrease with further undercooling. EBSD analysis revealed that, for ΔT > 181 K, two distinct types of grains appeared in the microstructure: one larger and the other much smaller. Under low undercooling conditions, the grains grew anisotropically with a preferred orientation, while under high undercooling, there was no apparent preferred growth orientation. Many twin boundaries were observed in the high-undercooling samples, which were further confirmed by TEM analysis. Additionally, both twin boundaries and high-angle grain boundaries increased gradually with undercooling.
- Open Access
Rapid Solidification of Invar Alloy
The Invar alloy has excellent properties, such as a low coefficient of thermal expansion, but there are few reports about the rapid solidification of this alloy. In this study, Invar alloy solidification at different undercooling (ΔT) was investigated via glass melt-flux techniques. The sample with the highest undercooling of ΔT = 231 K (recalescence height 140 K) was obtained. The thermal history curve, microstructure, hardness, grain number, and sample density of the alloy were analyzed. The results show that with the increase in solidification undercooling, the XRD peak of the sample shifted to the left, indicating that the lattice constant increased and the solid solubility increased. As the solidification of undercooling increases, the microstructure changes from large dendrites to small columnar grains and then to fine equiaxed grains. At the same time, the number of grains also increases with the increase in the undercooling. The hardness of the sample increases with increasing undercooling. If ΔT ≥ 181 K (128 K), the grain number and the hardness do not increase with undercooling.
Open AccessRapid Solidification of Invar Alloy
The Invar alloy has excellent properties, such as a low coefficient of thermal expansion, but there are few reports about the rapid solidification of this alloy. In this study, Invar alloy solidification at different undercooling (ΔT) was investigated via glass melt-flux techniques. The sample with the highest undercooling of ΔT = 231 K (recalescence height 140 K) was obtained. The thermal history curve, microstructure, hardness, grain number, and sample density of the alloy were analyzed. The results show that with the increase in solidification undercooling, the XRD peak of the sample shifted to the left, indicating that the lattice constant increased and the solid solubility increased. As the solidification of undercooling increases, the microstructure changes from large dendrites to small columnar grains and then to fine equiaxed grains. At the same time, the number of grains also increases with the increase in the undercooling. The hardness of the sample increases with increasing undercooling. If ΔT ≥ 181 K (128 K), the grain number and the hardness do not increase with undercooling.