Modeling and analysis of dry friction in micro-forming of metals

The Tabor friction model was modified by introducing the friction factor. Based on the multi-region model, the micro-uniaxial compression process was simulated to study the size effect considering dry friction. It was found that the grain-boundary has little effect on the dry friction behavior. The mechanical properties of individual grains either in the contact area or in the non-contact area have a significant influence on the friction behavior. With decrease of specimen's size, the average friction coefficient did not vary much but the value of friction coefficient of each random grain orientation distribution becomes more dispersive.

► We propose a grain region and grain-boundary region model available for micro-forming.
► We modify the Tabor friction model by introducing the friction factor for analyzing friction behavior of micro-forming.
► The properties of individual grains have a great influence on friction behavior of micro-forming.
► Friction coefficient is more dispersive in each specimen with the decrease of specimen's size.