On the Origin of Plasticity-Induced Microstructure Change under Sliding Contacts

TL;DR

This paper uses discrete dislocation plasticity simulations to explore how sliding contacts induce microstructure changes in single crystals, linking lattice rotations and stored energy to experimental tribological observations.

Contribution

It introduces a detailed DDP modeling approach to identify the mechanisms behind microstructure evolution under sliding contact conditions.

Findings

Lattice rotations and stored energy drive microstructure change.

Surface slip initiation correlates with contact size and load.

Insights for optimizing interface and material properties for frictional applications.

Abstract

Discrete dislocation plasticity (DDP) calculations are carried out to investigate the response of a single crystal contacted by a rigid sinusoidal asperity under sliding loading conditions to look for causes of microstructure change in the dislocation structure. The mechanistic driver is identified as the development of lattice rotations and stored energy in the subsurface, which can be quantitatively correlated to recent tribological experimental observations. Maps of surface slip initiation and substrate permanent deformation obtained from DDP calculations for varying contact size and normal load suggest ways of optimally tailoring the interface and microstructural material properties for various frictional loads.