Correlation of Sample Geometry and Grain Size in Micro-Bending of Electrodeposited Polycrystalline Gold

In this study, micro-cantilevers are fabricated from electrodeposited gold by focus ion beam system, and correlations of the sample geometry effect and average grain size on the bending characteristics are evaluated. The average grain size of all as-fabricated micro-cantilevers is measured to identify contributions of each of the sample geometry effect and average grain size to the micro-mechanical strength. The micro-cantilever with a finer average grain size shows a higher yield stress as a result of the grain boundary strengthening mechanism. The sample geometry effect is confirmed when varying the width and thickness of the micro-cantilever, which the yield stress is more dependent on the thickness than that on the width.