2025/09/08 by Fischer, Tim, Huber, Norbert
#Finite element method #Microcompression #Micromechanics #Nanoporous gold #Plasticity #Technology::620: Engineering::620.1: Engineering Mechanics and Materials Science
paper · doi:10.15480/882.15832
Micropillar compression testing is essential for understanding bulk metal plasticity at small scales and has emerged as a key technique for evaluating nanoporous metals like nanoporous gold (NPG). To support experimental design, we present a computational plasticity study on single crystal NPG micropillars, systematically examining four extrinsic factors: pillar height-to-diameter ratio (1.5 ≤ ℎ∕𝑑 ≤ 2.5), taper angle (0 ≤ 𝜃 ≤ 4◦), friction coefficient (0.0 ≤ 𝜇 ≤ 0.2), and misalignment angle (0 ≤ 𝛼 ≤ 2◦). The study reveals that NPG exhibits similar trends to its bulk counterpart but is less prone to post-yield buckling in unstable crystal orientations. For optimal NPG pillar stability, an aspect ratio of 1.5 ≤ ℎ∕𝑑 ≤ 2 is recommended and a moderate taper angle (𝜃 ≈ 2◦) to prevent artificial stiffening and yielding. Even minimal friction (𝜇 ≈ 0.05) enhances stability, while buckling is mainly governed by misalignment, requiring 𝛼 ≤ 1◦ to also avoid underestimating the elastic modulus.