Modeling and analysis of wire motion during rocking mode diamond wire sawing of mono-crystalline alumina oxide wafer

Wire sawing has been a primary method for slicing of silicon, silicon carbide, and sapphire for over two decades. Diamond wire sawing has offered faster and cleaner means as compared to slurry wire sawing. Diamond wire contact with workpiece along with other factors such as feed rate and wire diameter has resulted in the increase of normal cutting force. Contact length strongly affects abrasive numbers in the slicing area which further influences slicing performance in terms of material removal, surface topography, and sub-surface damage. This study developed a mathematical model to develop wire web and to evaluate contact length during rocking mode diamond wire sawing process. Effect of rocking mode along with rocking angle on wire web and further on contact length between wire and workpiece is studied with matlab simulations and results are compared with experiments. Results demonstrated that rocking mode reduces the contact length to almost half and decreases the equivalent chip thickness to improve the surface roughness. However, there is minimal effect of rocking angle on contact length. Saw marks model has been verified with experiments on sapphire or mono-crystalline alumina oxide wafer. It is observed that saw marks obtained from simulation is in agreement with experimental results. The results can extend the further investigation on rocking mode diamond wire sawing for slicing of brittle materials for better sub-surface damage.