Experimental and numerical investigation of the abrasive waterjet machining of aluminum-7075-T6 for aerospace applications

Abstract

The machining of hard-to-cut materials with a high degree of precision and high surface quality is one of the most critical considerations when fabricating various state-of-the-art engineered components. In this investigation, a comprehensive three-dimensional model was developed and numerically simulated to predict kerf profiles and material removal rates while drilling the aluminum-7075-T6 aerospace alloy. Kerf profile and material removal prediction involved three stages: jet dynamic flow modeling, abrasive particle tracking, and erosion rate prediction . Experimental investigations were conducted to validate the developed model. The results indicate that the jet dynamic characteristics and flow of abrasive particles alter the kerf profiles, where the top kerf diameter increases with increasing jet pressure and standoff distance. The kerf depth and hole aspect ratio increase with jet pressure, but decrease with standoff distance and machining time. Cross-sectional profiles were characterized by progressive edge rounding and parabolic shapes. Defects can be minimized by utilizing high jet pressure and small standoff distance. The material removal rate increases with increasing jet pressure, abrasive particle size, and exposure time, but decreases with increasing standoff distance.