Optimization of abrasive water jet machining process parameters of Al 7071 using design of experiments

Abstract

In recent times, Taguchi’s statistical approach in favour of development of face excellence and product types in abrasive water jet machining of aluminium and its alloys has turn out to be increasingly more widespread in various aircraft, ship building, and automation sectors. The present work made an attempts to identify the optimized parameter combination in abrasive water jet machining (AJWM) of aluminium 7071alloy (Al 7071). AJWM experiments were conducted based on Taguchi design of experiments. Machining parameters of traverse speed, SiC-abrasive flow rate and stand-off distance were taken as input parameters. For this purpose, Taguchi’s design of experiments selecting L9 orthogonal array was carried out in order to collect the material removal rate and surface roughness values. Furthermore, the control of process parameters on material removal rate as well as surface roughness has been measured by means plots and analysis of variance. Experiment number 9 through traverse speed of 300 mm min−1, 500 g min−1 of SiC-abrasive flow rate and 1 mm stand-off distance were identified as the best parameter combinations for maximum material removal rate. However, experiment number 1 through traverse speed of 100 mm min−1, 300 g min-1 SiC-abrasive flow rate and 0.5 mm stand-off distance were identified as the best parameter combination for improved surface finish. The microstructure of machined surfaces using scanning electron microscopy reveled that AWJM produced different zones along the cut surface of Al 7071and waviness and striations were increased marginally with SiC-abrasive flow rate.