Auxetic properties of polycrystals

TL;DR

This paper investigates the auxetic properties of polycrystalline solids, revealing that their stability regions for auxetic behavior are larger compared to monocrystals, with implications for material design.

Contribution

It provides a comparative analysis of auxetic regions in polycrystals versus monocrystals, highlighting expanded auxeticity zones in polycrystalline materials.

Findings

Polycrystals have larger auxetic regions than monocrystals.

The study focuses on 2D quadratic and 3D cubic grain structures.

Auxetic properties depend on grain orientation and crystal symmetry.

Abstract

Young's and shear moduli and Poisson's ratio of polycrystalline solids consisting of 2D quadratic and 3D cubic randomly oriented grains of the same size and shape is studied. Considered polycrystals are initially unstrained. It is shown that for such polycrystals the division of the mechanical stability regions into areas of various auxeticity properties is different than for monocrystalline solids. In particular the regions of complete auxeticity enlarge.