Abstract: The minimum energy requested for abrasive waterjet cutting is presented by a proposed concept of erosion index. Derived from the Newton law and Hertz equation, a dimensionless quantity, called the relative erosion strength, is found to be a constant during the impacting of an abrasive particle on ductile materials. Furthermore, the particle velocity in abrasive waterjet is computed based on a multiphase dynamic model which especially includes the effect of air flowrate on the particle acceleration process in the mixing tube, a critical part to form the abrasive waterjet. Finally, an experimental system with an air flowrate regulator is set up to measure the erosion index. The results show that the erosion index can be applied to predict abrasive waterjet cutting performance.

Key words: Abrasive waterjet, Cutting, Erosion index