Low friction in bcc metals via grain boundary sliding

• DOI: 10.1103/physrevmaterials.4.063602
• Publication Date: 2020-06-09T13:45:02Z
• Authors: Adam R. Hinkle; John F. Curry; Hojun Lim; Brendan L. Nation; Morgan R. Jones; John Wellington-J...; Ping Lu; Nicolas Argibay; Michael Chandross
• Keywords: Grain Boundary Sliding; Grain boundary strengthening

Low friction is demonstrated with pure polycrystalline tantalum sliding contacts in both molecular dynamics simulations and ultrahigh vacuum experiments. This phenomenon shown to be correlated deformation occurring primarily through grain boundary can explained using a recently developed predictive model for the shear strength of metals. Specifically, low associated sizes at interface being smaller than critical, material-dependent value, where crossover from dislocation mediated plasticity grain-boundary occurs. therefore inverse Hall-Petch behavior softening interface. Direct quantitative comparisons between experiments atomistic calculations are used illustrate accuracy predictions.