Analysis of Ring-Crack Initiation in Hertz Indentation of Monocrystalline Si Using Analytical Solution Controlled-MD

Abstract

In order to study an unknown mechanism of defect initiation in Hertz indentation of monocrystalline silicon with no preexisting defect, analytical solution controlled-MD simulation proposed by the authors has been carried out using an MD model embedded on the surface of silicon. It has been shown that a defect that will become a ring crack can be generated just outside the outer periphery of the contact area between the silicon and indenter. The mechanism of the defect initiation is that the dynamic force associating with acoustic waves transforms monocrystal structure to polycrystal one at the outer periphery of the contact area and this phase change under a macroscopic/static tensile stress acting there triggers cross slips which result in micro-void defects.