A multigrains׳ approach to model the micromechanical contact in glass finishing

This work addresses the influence of grains׳ interaction on the material removal volume and damage development in multigrain contact conditions. Based on certain assumptions and idealized conditions, multiple-grain contact conditions were modeled. The abrasive grains of grinding tool are locally modelled by three sharp tips. The material removal process is hence investigated in relation to the distance separating the indenters. Single scratch test (SST) and Triple scratch test (TST) are basically conducted. The experimental tests used four speeds and five separation distances ranging, respectively, in 16-64 m min−1 and 100-800μm. The depth of cut is however kept constant at 0.1 mm. The experimental set-up uses a Kistler piezoelectric dynamometer for in situ force acquirements. Profilometry and optical microscopy are also used to investigate groove characteristics (depth, width and material removed volume). The experimental findings showed that for a given separation distance, there exists a critical speed for which the interaction reaches a threshold point. There is also a critical separation distance where full interaction occurs and the material removal volume is the maximum. In TST the cracks induced by the neighbouring scratches may intersect with each other, leading to an extensive chipping. The results demonstrate that the cumulative interaction between grains is profitable for the material removal process while the separation distance between abrasive grains is well controlled.