Modelling of contact regimes in wire sawing with dissipative particle dynamics

Optimization of the wire sawing process of silicon ingots requires a profound understanding of the dynamic interaction of wire, slurry and silicon material. In this paper, the influence of wire velocity and applied wire stress on the process is investigated using dissipative particle dynamics and discrete element simulations for modelling the fluid and the grains in the abrasive suspension. In our simulations, different contact regimes occur depending on grain shape and a stress balance within the system. We observed semi-contact for high wire stress and low wire velocity and non-contact for low stress and high velocities in agreement with predictions from elasto-hydrodynamic modelling. Our simulations suggest the usage of sharp grains, since in this case, stress localization on the base of the sawing groove occurs even in the non-contact regime. These insights are likely to provide a scientific base for the optimization of sawing rates and reduction of kerf loss.