Evolution of Microstructure during Rapid Solidification of SiC under High Pressure

Wanjun Yan,Xinmao Qin,Chunhong Zhang,Zhongzheng Zhang,Tinghong Gao,Maheswar Nayak

doi:10.1155/2022/7823211

Wanjun Yan, Xinmao Qin + Show 4 more

Open Access

https://doi.org/10.1155/2022/7823211

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Abstract

The microstructure evolution of liquid silicon carbide (SiC) during rapid solidification under different pressure values is simulated with the Tersoff potential using molecular dynamics. The structure evolution characteristics of SiC are analyzed by considering the pair distribution function, bond angle distribution, coordination number, and the diagrams of the microstructure during rapid solidification. The results show that the average energy of atoms gradually increases with pressure. When the pressure reaches 100 GPa, the average energy of the atom is greater than the average energy of the atom in the initial liquid state. Under different pressures, the diffusion of atoms tends to remain stable at a temperature of about 3700 K. The application of pressure has a major impact on the arrangement of atoms, except on the third-nearest neighbor, while the impact on the nearest neighbor and the second-nearest neighbor is relatively small. The pressure increases the medium-range order of the system. The coordination numbers of Si and C atoms gradually decrease with the decrease in temperature and increase in pressure. Pressure changes the microstructure of the SiC amorphous system after solidification, and the density can be increased by adjusting the coordination number of atoms. As the pressure increases, the SiC amorphous system exhibits a dense structure with coordination numbers of 4, 5, 6, and 7.

Highlights

Silicon carbide (SiC) has excellent physical and mechanical properties, such as low density, high specific strength, and high-temperature resistance
When the pressure reaches 100 GPa, the average energy of the atoms becomes greater than the average energy of the atoms in the initial liquid state. e reason for this change is that the interatomic distance in the liquid SiC system gradually reduces with the increase in pressure
The pressure changes the microstructure of the SiC amorphous system after solidification, and the density is increased as a result of the changes in Coordination Number (CN) atoms

Summary

Introduction

Silicon carbide (SiC) has excellent physical and mechanical properties, such as low density, high specific strength, and high-temperature resistance. It has great application prospects in fabricating weapon armor, coatings, engine turbine blades, and friction and electronic devices [1]. Extensive experimental research has been conducted to study the elastic deformation and phase transition of SiC under high pressures. MD is especially suitable for the study of dynamic physical and mechanical property changes of materials under extreme loading [17, 18]. E evolution of the microstructure provides theoretical guidance for the study of the physical and mechanical properties of SiC under extreme service conditions and can be the basis of the design of related materials and structures SiC is one of the materials necessary for fabricating extreme electronic devices. e study of the rapid solidification process of SiC under high pressure is necessary. erefore, the MD simulation method is used to simulate the rapid solidification process of SiC under different pressures and to study the influence of pressure on the dynamic behavior and microstructure of SiC. e evolution of the microstructure provides theoretical guidance for the study of the physical and mechanical properties of SiC under extreme service conditions and can be the basis of the design of related materials and structures

Simulation Conditions and Methods

Results and Analysis

Microstructure Analysis

Conclusion