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.

中文翻译：

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高压下 SiC 快速凝固过程中的显微组织演变

液体碳化硅（SiC）在不同压力值下快速凝固过程中的微观结构演变采用分子动力学的 Tersoff 势进行模拟。结合快速凝固过程中的对分布函数、键角分布、配位数和显微组织图，分析了SiC的组织演化特征。结果表明，原子的平均能量随着压力的增加而逐渐增加。当压力达到 100 GPa 时，原子的平均能量大于初始液态原子的平均能量。在不同的压力下，原子的扩散在大约 3700 K 的温度下趋于保持稳定。压力的施加对原子的排列有很大的影响，除了第三近邻，而对最近邻和次近邻的影响相对较小。压力增加了系统的中程阶数。Si和C原子的配位数随着温度的降低和压力的增加而逐渐减小。压力改变了凝固后的SiC非晶体系的微观结构，可以通过调节原子的配位数来增加密度。随着压力的增加，SiC 非晶体系呈现出致密的结构，配位数分别为 4、5、6 和 7。压力改变了凝固后的SiC非晶体系的微观结构，可以通过调节原子的配位数来增加密度。随着压力的增加，SiC 非晶体系呈现出致密的结构，配位数分别为 4、5、6 和 7。压力改变了凝固后的SiC非晶体系的微观结构，可以通过调节原子的配位数来增加密度。随着压力的增加，SiC 非晶体系呈现出致密的结构，配位数分别为 4、5、6 和 7。