The machinability of AZ31 magnesium alloy was investigated using abrasive water jet (AWJ) machining with emphasis on the effects of stand.off distance (SOD), feed rate, and number of machining passes on material removal rate (MRR) and kerf width. Experimental results revealed that increasing SOD from 1 to 3 mm and increasing the number of passes from one to three enhanced MRR by 25.02% and 38.2%, respectively, whereas increasing feed rate from 104 to 186 mm/min led to a 32.9% reduction in MRR. Kerf width increased by ~29% with higher stand.off distance and by ~21% with additional passes due to enhanced lateral erosion, while an intermediate feed rate reduced kerf width by ~19% by improving jet stability. An artificial neural network model demonstrated high predictive accuracy (R 2 ≈ 0.98), and Grey relational analysis identified optimal machining conditions for simultaneous maximization of MRR and minimization of kerf width. ANOVA results revealed that feed rate contributed 49.88% toward MRR variation, whereas SOD and feed rate contributed 35.44% and 35.41%, respectively, toward kerf-width variation. The ANN model achieved an overall prediction accuracy of R 2 = 0.9843. Multi-response optimization identified SOD = 3 mm, feed rate = 104 mm/min, and one pass as the optimal condition. Microstructural analysis confirmed ductile erosion without heat.affected zones or abrasive embedment, indicating that AWJ machining is a thermally safe and effective process for machining AZ31 magnesium alloy. These findings demonstrate the suitability of AWJM for sustainable and thermally safe machining of AZ31 Mg alloy.
Doreswamy et al. (Fri,) studied this question.