Peridynamics破壊力学と分子動力学の連携によるSiC押込み試験の解析

抄録

In recent years, silicon carbide (SiC) has attracted attention as an alternative material to monatomic silicon improving the performance of power conversion equipment. However, SiC is mechanically and chemically very stable, and it is necessary to understand intrinsic plastic deformability for high precision processing of thin film. Therefore, in order to acquire characteristics in the processing, we will elucidate the mechanism for a process-induced degradation layer which is generated to nanometer size, possibly occurring during surface polishing. In this study, we investigate plastic deformability by a multiscale analysis integrating both molecular dynamics (MD) and peridynamics(PD) theory. In particular, an nanoindentation test of SiC is carried out by using MD method first, and then the elastic properties are extracted from the force curve. Then, these values are applied to PD theory, and a multiscale analysis is conducted. These methods are currently under scrutiny. In this report, we will describe the result using material property values already obtained by experiments and others. The force curve obtained in PD simulation is consistent with the solution obtained by Hertzian theory, and it shows plastic deformation behavior. As the indenter goes in, damage of each particles increases, and subsequently cracks and fracture (regional breakdown) occur. Furthermore, when a parameter of critical stretch between particles which is adjusted to fit to tensile strength and Young's modulus, uplift movement of damaged particles around the contact surface can be confirmed, that agrees well with the same kind of experiment.