A comprehensive parametric study on abrasive waterjet trepanning of Al-6061 alloy
Rajesh Ravi, D.S. Srinivasu
Abstract
Abrasive waterjet (AWJ) can be used to realize holes of any size and shape in difficult-to-machine ductile materials with negligible heat-affected zone by simply changing the jet path. In this study, the influence of various process parameters, such as waterjet pressure (P), jet traverse speed (νf), abrasive mass flow rate (ma) on the AWJ-trepanned hole’s geometrical features (diameter, taper angle, profile), form characteristics (circularity error, cylindricity error), quality measures (damage region, edge radius, burr formation, uncut material, surface morphology), and material removal mechanism in Al-6061 alloy is studied. The results show that higher P and ma at lower νf are desirable for achieving nominal geometrical features, minimal form error, burr length, and uncut material. Damage region reduces with the decrease in P and ma at higher νf. Edge radius reduces with the increase in P at lower νf and ma. The micrographs showed that the initial damage region is uniform at higher P and lower νf. Better surface quality is obtained at higher P and ma as lip formation and material pile-up are minimum. Material fracture and cracks in the vicinity of the burr are observed. Based on the mean response analysis, near-optimal parameters are suggested for efficient trepanning.