Mechanical activation in mechanical removal of GaN using diamond tip and mechanochemical removal using Al2O3 tip are described by the Archard equation and mechanically assisted Arrhenius-type kinetic model, respectively. Evident material-removal under elastic contact occurs with the assistance of interfacial mechanochemical reactions. By analyzing the mechanochemical reactions with Arrhenius-type kinetic model and Hertzian contact mechanics, the critical activation volume and activation barrier are determined semiquantitatively. The mechanical activation originating from the chemically active counter-surface facilitates the mechanochemical atomic attrition by altering the energy barrier of the reaction kinetics. This work can provide deep insights into the mechanochemical-removal mechanism of GaN.

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Contact Dynamics

Guo, J, Xiao, C, Gao, J, Li, G, Wu, H, Lei, C, & Qian, L. (2021). Interplay between counter-surface chemistry and mechanical activation in mechanochemical removal of N-faced GaN surface in humid ambient. Tribol.Int., 159, 107004: 1–107004: 9. doi:10.1016/j.triboint.2021.107004