Molecular dynamics simulation of nanoindentation on nanocomposite pearlite

TL;DR

This study uses molecular dynamics simulations to explore how cementite size and temperature influence deformation and dislocation behavior in nanocomposite pearlite, revealing mechanisms of dislocation blocking and plastic deformation distribution.

Contribution

It provides new insights into the dislocation propagation mechanisms and the effects of cementite thickness and temperature on nanocomposite pearlite's deformation behavior.

Findings

Dislocation propagates via widespread plastic deformation in cementite.

Increasing temperature enhances plastic strain distribution in ferrite.

Thickening cementite or raising temperature reduces dislocation transmission through cementite.

Abstract

We carry out molecular dynamics simulations of nanoindentation to investigate the effect of cementite size and temperature on the deformation behavior of nanocomposite pearlite composed of alternating ferrite and cementite layers. We find that, instead of the coherent transmission, dislocation propagates by forming a widespread plastic deformation in cementite layer. We also show that increasing temperature enhances the distribution of plastic strain in the ferrite layer, which reduces the stress acting on the cementite layer. Hence, thickening cementite layer or increasing temperature reduces the likelihood of dislocation propagation through the cementite layer. Our finding sheds a light on the mechanism of dislocation blocking by cementite layer in the pearlite.