Particle kinetic energy-based modeling and experimental study on abrasive waterjet coating removal

Abrasive waterjet coating removal is a surface treatment and recovery technique that is highly efficient and low in energy consumption. It also can create well defined surface texture and normally requires inexpensive equipment, thus has been extensively used in industrial remanufacturing and large-scale equipment maintenance practices. To optimize this process in terms of the coating removal rate of abrasive waterjet, it is of critical importance to establish physic based quantitative model. Currently, existing theoretical models can only predict abrasive waterjet erosion depth and a model which can predicted removal area per unit time is needed. In this study, a particle kinetic energy-based model for predicting removal width was proposed, and the energy coefficient was obtained from experimental measurement. Experimental research on quantifying the abrasive waterjet coating removal process and effects of jet parameters such as jet pressure, nozzle traverse speed and traverse numbers on coating removal width were conducted. The test results showed that the main factors affecting the width were the kinetic energy of particle and impact duration. Removal width increased with particle kinetic energy and impact time. Under current experimental setup, the width removed coating track created by abrasive waterjet was 4.12 mm with an inlet pressure of 6 MPa, nozzle diameter of 1.02 mm, traverse speed of 1 mm/s, which is about 3 times larger than the width removed using a pure waterjet with pressure of 35 MPa. Water and energy consumption using abrasive waterjet removal is much smaller than those of pure waterjet. The removal width value results, with the R2 value of 0.95 when comparing the predicted value and measured results, as a function of number of traverse jet passes.