In situ analysis of flow characteristic and deformation field of metal surface in sliding asperity contact

Abstract

This work uses a model in situ configuration to explore the surface flow characteristics of a soft metal surface sliding against a hard wedge, representative of surface asperity. Digital image analysis shows that a sharp wedge triggers the non-laminar flow of materials which moves the strain rate field closure to the surface, causes surface folding, and generates cracks-likes features on the slid surface. Whereas, a blunt wedge with a large tip radius promotes laminar flow and suppresses the cracks. The transition of flow from laminar to non-laminar mode is discussed in terms of the underlying deformation characteristic of sliding wedges.