Elastic constants of polycrystalline steel evaluated with laser generated surface acoustic waves

TL;DR

This paper introduces a laser-based surface acoustic wave technique to measure elastic constants of micro-crystals in polycrystalline steel, enabling non-destructive characterization of material properties.

Contribution

The study presents a novel laser-generated surface acoustic wave method for evaluating elastic constants of micro-crystals in polycrystalline steel, including a way to solve the inverse problem for cubic symmetry.

Findings

Successfully measured surface wave velocities in micro-crystals.

Determined three elastic constants of cubic symmetry micro-crystals.

Potential for extending the method to texture and weld characterization.

Abstract

We report on a laser generated and detected surface acoustic wave method for evaluating the elastic constants of micro-crystals composing polycrystalline steel. The method is based on the measurement of surface wave velocities in many micro-crystals oriented randomly relative to both the wave propagation direction and the sample surface. The surface wave velocity distribution is obtained experimentally thanks to the scanning potentiality of the method and is then compared to the theoretical one. The inverse problem can then be solved, leading to the determination of three elastic constants of the cubic symmetry micro-crystals. Extensions of the method to the characterization of texture, preferential orientation of micro-crystals or welds could be foreseen.