Date of this Version
Proceedings of the National Academy of Sciences
We study the uniaxial compressive behavior of disordered colloidal free-standing micropillars composed of a bidisperse mixture of 3- and 6-μm polystyrene particles. Mechanical annealing of confined pillars enables variation of the packing fraction across the phase space of colloidal glasses. The measured normalized strengths and elastic moduli of the annealed freestanding micropillars span almost three orders of magnitude despite similar plastic morphology governed by shear banding. We measure a robust correlation between ultimate strengths and elastic constants that is invariant to relative humidity, implying a critical strain of ∼0.01 that is strikingly similar to that observed in metallic glasses (MGs) [Johnson WL, Samwer K (2005) Phys Rev Lett 95:195501] and suggestive of a universal mode of cooperative plastic deformation. We estimate the characteristic strain of the underlying cooperative plastic event by considering the energy necessary to create an Eshelby-like ellipsoidal inclusion in an elastic matrix. We find that the characteristic strain is similar to that found in experiments and simulations of other disordered solids with distinct bonding and particle sizes, suggesting a universal criterion for the elastic to plastic transition in glassy materials with the capacity for finite plastic flow.
© 2014 National Academy of Sciences.
plasticity in disordered solids, shear transformation, cooperative deformation, Eshelby inclusion, colloidal glasses
Strickland, D. J., Huang, Y., Lee, D., & Gianola, D. S. (2014). Robust Scaling of Strength and Elastic Constants and Universal Cooperativity in Disordered Colloidal Micropillars. Proceedings of the National Academy of Sciences, 111 (51), 18167-18172. http://dx.doi.org/10.1073/pnas.1413900111
Date Posted: 25 October 2017
This document has been peer reviewed.