Effect of tilt and twist angles on the cleavage crack propagation

TL;DR

This paper investigates how tilt and twist angles at grain boundaries influence cleavage crack propagation, combining fracture mechanics modeling with experimental EBSD analysis to understand microstructural effects.

Contribution

It introduces a fracture mechanics model that predicts crack deviation based on tilt and twist angles, validated by EBSD analysis.

Findings

Model accurately predicts crack deviation due to tilt and twist angles.

EBSD analysis confirms microstructural features align with model predictions.

Microstructural features at grain boundaries influence crack propagation behavior.

Abstract

We report the mechanism of cleavage crack deviation at grain boundaries. A fracture mechanics based model has been developed to combine the effect of tilt and twist angles between cleavage planes on the reduction in normalized energy release rate. Furthermore, electron back-scatter diffraction analysis on cleavage fracture surface has been carried out. The microstructural features associated with the presence of tilt and twist angle at the grain boundary have been identified and found to be consistent with the prediction from the analytical model.