A comprehensive investigation of geometrical accuracy errors during WEDM of Al6061-7.5%SiC composite

Abstract

Al-matrix composites specifically Al6061-7.5%SiC which holds promising mechanical properties, is a potential candidate in aeronautical industry. Though the reinforcement of SiC in Al-substrate has appreciably enhanced the mechanical characteristics, but it complicates its machining as the composite bears excellent hardness and strength. Moreover, its intended applications require the formation of intricate profiles. Therefore, the processing/machining of such composite is challenging. Wire electric discharge machining (WEDM) is an appreciable choice for Al6061-7.5%SiC machining. However, intrinsic issues of WEDM, i.e., wire vibrations and lag have resulted in a compromised dimensional accuracy of machined part. Furthermore, realization of similar errors' magnitude in both the cutting orientations (axial; E(XD)and lateral; E-YD) is difficult because of the presence of SiC-reinforcement which is a stimulus for wire disturbances. Similarly, this reinforcement influences corner accuracy and makes it's tedious to attain same corner errors at both faces (top; AE(TOP)and bottom; AE(BOT)). These accuracy issues have not been discussed yet which is primarily done herein using response surface methodology. Statistical, optical, and SEM analyses are performed for detailed understanding of the parametric effects. The minimum error values achieved are 0.01 mm, 0.105 mm, 0.249 degrees and 0.475 degrees in case of E-XD, E-YD, AE(TOP)and AE(BOT)respectively.