We examine the impact of a two-scale surface design scheme for the control of friction, lubri-cation and wear in a laboratory forging process. The design scheme proposes the use of die and/or workpiece surface topographies that consist of an array of meso-scale cavities superimposed on a micro-scale background of interconnected channels. The cavities act as lubricant reservoirs from which lubricant is pumped into the smaller channels through plastic deformation of workpiece material into the cavities. The channels provides the means by which lubricant is then transported to regions of the interface that might otherwise becoem depleted of lubricant. Forging experiments were conducted to test the design scheme with various combinations of die-workpiece surface topographies. The experimental results from one such combination were compared with the predictions of a finite element model. The results provided fundamental insight into workpiece material extrusion into the cavities, and the efficiency of lubricant transport by the fine-scale background of interconnected channels.
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