Multi-objective optimization of AAJM process parameters for cutting of B4C/Gr particles reinforced Al 7075 composites using RSM-TOPSIS approach

The present study deals with the machining of hybrid Al 7075/B4C/Gr composite using Abrasive Aqua Jet Machining. The effects of selected input factors, i.e., water jet pressure (WJP), stand-off distance (SOD), and traverse speed (TS) on the performance characteristics, namely taper angle (TA), surface roughness (Ra), and the material removal rate (MRR) are investigated. The experimental runs and test strategies are formulated using the Response Surface Methodology-Central Composite Design approach. Analysis of Variance (ANOVA) was used to examine the effect of input factors and their interactions with performance characteristics. MRR, Ra, and TA optimum condition and mathematical equations were also developed. Further, the multi-optimization method "Technique for Order of Preference by Similarity to Ideal Solution" is considered to find out the best combinations of input factors for optimized output factors on the hybrid composite. The ANOVA results confirm that among the input factors, WJP and SOD are the most significant factors, and the percentage distribution of input factors are found to be jet pressure (55.21%), stand-off distance (23.36%), and traverse speed (2.56%). The multi-objective optimum conditions of the input factors are WJP (A(1)) 210 bar, SOD (B-1), and TS (C-3) 30 mm/min, that produce optimal values of the considered responses, i.e., MRR up to 4.8703 mm(3)/min, Ra up to 3.57 mu m and TA up to 0.189 degrees. The TA has improved by 49.6% through the multi-objective optimum results when compared with single parameter optimized results.