FRACTURE MECHANICS-BASED MODEL OF ABRASIVE WATERJET CUTTING FOR BRITTLE MATERIALS

Advanced engineering ceramic materials such as silicon carbides and si licon nitride have been used in many engineering applications. The abr asive waterjet is becoming the most recent cutting technique of such m aterials because of its inherent advantages. In the present study, two elastic-plastic erosion models are adopted to develop an abrasive wat erjet model for cutting brittle materials. As a result, two cutting mo dels based on fracture mechanics are derived and introduced. The sugge sted models predict the maximum depth of cut of the target material as a function of the fracture toughness and hardness as well as the proc ess parameters.It is found that both models predict the same depth of cut within a maximum of approximate to 11%, for the practical range of process parameters used in the present study. The maximum depth of cu t predicted by the suggested models are compared with published experi mental results for three types of ceramics. The effect of process para meters on the maximum depth of cut for a given ceramic material is als o studied and compared with experimental work. The comparison reveals that there is a good agreement between the models' predictions and exp erimental results, where the difference between the predicted and expe rimental value of the maximum depth of cut is found to be an average v alue of 10%.