AVS 63rd International Symposium & Exhibition
    Tribology Focus Topic Wednesday Sessions
       Session TR+AS+NS+SS-WeA

Invited Paper TR+AS+NS+SS-WeA1
A Multi-Bond Model of Single-Asperity Wear at the Nano-Scale

Wednesday, November 9, 2016, 2:20 pm, Room 101A

Session: Nanoscale Wear: Applications to Nanometrology and Manufacturing
Presenter: Michael L. Falk, Johns Hopkins University
Authors: Y. Shao, Johns Hopkins University
T.D.B. Jacobs, University of Pittsburgh
M.L. Falk, Johns Hopkins University
Correspondent: Click to Email
Single-asperity wear experiments and simulations have identified different regimes of wear including Eyring- and Archard- like behaviors. A multi-bond dynamics model based on Filippov et al. [Phys. Rev. Lett. 92, 135503 (2004)] captures both qualitatively distinct regimes of single-asperity wear under a unifying theoretical framework. In this model, the interfacial bond formation, wear-less rupture and transfer of atoms are governed by three competing thermally activated processes. The Eyring regime holds under the conditions of low load and low adhesive forces; few bonds form between the asperity and the surface and wear is a rare and rate-dependent event. As the normal stress increases the Eyring-like behavior of wear rate tends to break down. A nearly rate-independent regime holds under high load or high adhesive forces; bonds form readily and the resulting wear is limited by the sliding distance. In a restricted regime of normal load and sliding velocity, the dependence of wear rate on normal load is nearly linear and independent of sliding velocity, as described by the Archard equation. Detailed comparisons to experimental and molecular dynamics simulation investigations have illustrated both Eyring and Archard regimes and an intermediate cross-over between the two.