Multi-objective optimization of surface roughness, recast layer thickness and surface crack density in WEDM of Al2124/SiCp using desirability approach

Engineered materials like Aluminum Metal Matrix Composites (ALMMCs) have tailor-made properties like high specific strength, low coefficient of thermal expansion (CTE), high thermal and electrical conductivity along with improved tribological properties. ALMMCs suitable for making the components used in automobile, and aerospace industry to enhance engine performance. In this paper, custom-made composite material Al2124/SiCP is machined by Wire cut Electric Discharge Machine (WEDM). The machining factors are pulse on time (T-on), pulse off time (T(of)f), current (IP), and servo voltage (SV) designed as per Central Composite Design (CCD). The response parameters, namely, Surface Roughness (SR), Recast Layer Thickness (RCT), and Surface Crack Density (SCD) are optimized by multi-objective optimization through desirability to improve the fatigue life of the component by selecting optimum input parameters. ANOVA results indicate that SR is influenced by T-on, SV, IP*SV, and T-on*T-on. RCT is influenced by T-on, T-off, IP, and T-on*SV. On the other hand, SCD is influenced by IP, IP*SV. The average values of SR, RCT, and SCD ranges between 1.369 and 3.325 mu m, 3.926-64.083 mu m, and 0.0449-0.1082 mu m/mm(2), respectively, for the range of input parameters. The confirmation experiments conducted at optimum design parameters (T-on = 119.056 mu s, T-off = 47.082 mu s, IP = 20 A, SV = 50 V) obtained through the desirability approach are found in reasonable agreement with the experimental results. (C) 2020 Elsevier Ltd. All rights reserved.