Simultaneous Necking and Barreling Deformation Behaviors in Bending of Single-Crystal Gold Micro-Cantilever

TL;DR

This paper studies how single-crystal gold micro-cantilevers deform under bending, revealing simultaneous necking and barreling behaviors.

Contribution

The study identifies a new 'sample geometry effect' linking deformation behaviors to crystal orientation and microstructure.

Findings

Necking and barreling occurred together in sample A due to four active slip systems.

Sample B showed slip band deformation with only one active slip system.

Thinner micro-cantilevers exhibited strengthening linked to cross-sectional geometry.

Abstract

Necking and barreling deformation behaviors occurred simultaneously during the bending test of a single-crystal gold micro-cantilever (sample A) with the loading direction parallel to the [1-10] orientation and the neutral plane parallel to the [110] orientation. In contrast, for another single-crystal gold micro-cantilever, sample B, with the loading direction aligned parallel to the [0.37 −0.92 0.05] orientation and the neutral plane parallel to the [0.54 0.28 0.78] orientation, predominant slip band deformation was noted. Sample A exhibited activation of four slip systems, whereas sample B demonstrated activity in only a single-slip system. This difference suggests that the presence of multiple slip systems contributes to the concurrent occurrence of necking and barreling deformations. Furthermore, variations in the thickness of the micro-cantilevers resulted in observable strengthening, indicating that the effect of sample size is intricately linked to the geometry of the cross-section, which we have termed the “sample geometry effect”.

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