Size effects in strength and plasticity of single-crystalline titanium micropillars with prismatic slip orientation

We present results of uniaxial compression experiments on rectangular prismatic titanium micropillars loaded along [11 (2) over bar0]. We find that flow stress increases significantly with decreasing pillar size down to 300 nm, with a slope of -0.5 on the log-log scale. The strength of 300 nm pillars is 1040 MPa, reaching 16% of the theoretical strength of titanium. We observe wavy lines for samples with diameters greater than 1 mu m. The critical resolved shear stress is inversely proportional to the sample size, consistent with dislocation source nucleation-controlled plasticity. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.