Atomistic Insights into the Phase Transformation of Single-Crystal Silicon during Nanoindentation

Abstract

The influence of the indenter angle on the deformation mechanisms of single-crystal Si was analyzed via molecular dynamics simulations of the nanoindentation process. Three different types of diamond conical indenters with semi-angles of 45°, 60°, and 70° were used. The load–indentation depth curves were obtained by varying the indenter angles, and the structural phase transformations of single-crystal Si were observed from an atomistic view. In addition, the hardness and elastic modulus with varying indenter angles were evaluated based on the Oliver–Pharr method and Sneddon’s solution. The simulation results showed that the indenter angle had a significant effect on the load–indentation depth curves, which resulted from the strong dependence of the elastic and plastic deformation ratios on the indenter angle during indentations.

An Overview of Mechanical Properties of Diamond-like Phases under Tension

“…As can be seen, the deformation behavior of all tubulanes is very similar, with an even close limit of the first phase transformation. Such phase transformations are very common for covalent crystals [ 64 ]. Despite this, phase transformation is of high interest, and it is not described in the present work since it requires special analysis.…”

“…The development of the reactive interatomic potentials for carbon [ 58 , 59 , 60 , 61 , 62 , 63 ] adopted molecular dynamics (MD) as one of the most used tools for numerical calculations in this field. Existing MD simulations allow for analyzing the phase transition during synthesis or deformation of carbon phases [ 39 , 64 ], their stability [ 65 ], and their properties in a wide variety of external effects [ 66 , 67 ]. MD simulations can be utilized as a phenomenological method to understand the deformation behavior in materials at the atomistic level.…”