A universal scaling law for the strength of metal micropillars and nanowires

The yield strength of sub-micron single-crystal metal pillars and wires increases with decreasing pillar diameter. Here, we show that the yield stress (resolved onto a slip system), sigma(rss), scaled by shear modulus, p, and the diameter, d, scaled by Burgers vector, b, shows the following universal correlation: sigma(rss)/mu = A(d/b)(m); for face-centred cubic (fcc) metals A = 0.71 and m = -0.66. Data for Mo and a Mo alloy are found to approximately obey the fcc correlation, despite having a different crystal structure. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.