## 1 Introduction
[PERSON] et al. [7] worked on Al6061 reinforced with boron carbide and graphite, manufactured using stir casting and heat-treated through two different processes, which were conventional and microwave-based heat treatment. The work also identifies current and pulse-on time as the major parameters contributing to MRR and surface roughness. The design values were identified to be 9 A current and 46 us pulse-on time for the optimum results. [PERSON] and [PERSON] [8] studied the mechanical properties of two different aluminium-based composites. It was concluded that the increase in the addition of graphite and SiC had enhanced the tensile strength and hardness, whereas addition of graphite in alumina-reinforced aluminium metal matrix composite does not provide any variation in tensile strength. [PERSON] and [PERSON] [9] carried out the study on the mechanical properties of the Al6061-fly ash-E-glass fibre composites. The work concluded that the addition of fly ash had improved the hardness and tensile strength by nearly 60-70%, whereas the addition of E-glass fibre had not shown any significant influence in the properties of the composite. [PERSON] et al. [10] worked on comparing the mechanical properties of Al6061 mixed with SiC and graphite as the reinforcements. It was observed in the work that the addition of 12% SiC as the reinforcement increased hardness by 50% and tensile strength by 60%, whereas the addition of the same percentage of graphite reduced the hardness by 25% but increased the tensile strength by 60%. [PERSON] et al. [11] studied the mechanical properties of Al6061 reinforced with SiC and titanium dioxide. The work identified that the tensile strength dropped when the addition of the reinforcement was more than 4% each in the matrix. However, hardness continued to increase with the increased reinforcement percentage. The hardness improvement was observed to be nearly 5.5% when 6% SiC and TiO\({}_{2}\) was added to the base matrix. [PERSON] et al. [12] studied the mechanical property of the Al6061 composite with different percentages of SiC. The work concluded that the hardness, as well as tensile strength of the composite, improved by 12.5% with 5% inception of SiC into the composite. [PERSON] et al. [13] worked on functionally graded aluminium matrix composites for machining parameters of surface roughness, electrode wear rate, overcut and power consumption in EDM. The work aimed for the application of the material in a disc-brake rotor. The work identified that the pulse current plays a major role in the output parameters. The optimised values of current and pulse-on time were identified to be 5 A and 50 \(\upmu\)s. [PERSON] and [PERSON] [14] conducted studies on the influence of the workpiece hardness on the EDM process for different alloys. It was identified in the work that the workpiece hardness and related parameters have significant influence on the surface roughness and MRR of the EDM process. The work aimed at developing a model based on the input data for steel, and identified that the derived model is able to predict the values with a maximum error of 5.2% for MRR and 0.8% for surface roughness to the experimental values. [PERSON] et al. [15] conducted a study on Al6061-SiC composite using different electrodes on its performance variation for MRR and surface roughness. It was identified that brass electrode provided a better MRR and surface finish when compared to copper and steel electrodes. The brass electrode provided 23.2% higher MRR and 20.3% better surface finish when compared with copper electrode. Steel electrode provided 35.3% and 32.3% less MRR and surface finish, respectively. [PERSON] [16] conducted a study on Al6061 with Al\({}_{2}\)O\({}_{3}\) as the reinforcement using grey relational analysis. The work identified that pulse current is the major factor in determining the MRR and surface roughness of the composite. [PERSON] et al. [17] conducted an experimental study for the machining of Al6061-7.5% SiC composite using wire EDM.