Optimisation of Process Parameters of EDM on Al6082/SiC Metal Matrix Composite 2016-01-0533

In the present investigation AA6082/ SiC MMC composite is fabricated using electromagnetic stir casting technique. Silicon carbide (SiC) of 40 μm size is used as reinforcement and is varied by weight percentage as 0%, 2.5%, 5%, 7.5%, 10% in alloy AA6082. The microstructure of the fabricated composite is studied by scanning electron microscopy (SEM) which shows even distribution of the reinforcement. The mechanical properties improve with SiCp till 7.5%, after that the properties decreases which may be due to presence of porosity during the composite manufacturing. A comparative study of mechanical properties such as tensile strength, hardness and toughness has been done between the composite and base aluminium alloy. After the comparative study it was found that the composite having AA6082/SiC-92.5%/7.5% is best suited. So, it is used for optimization of Electrical Discharge Machining (EDM) process parameters using Taguchi’s design of experiment. Process parameters of EDM are metal removal rate (MRR), surface roughness (SR) and tool wear rate. Using Taguchi’s parameter design, significant machining parameters affecting the performance measures are identified such as discharge current, and dielectric flushing pressure.L9 has been used to get optimal setting of control factors viz. current and dielectric flushing pressure for maximization of metal removal rate (MRR) and minimization of surface roughness (SR).The optimized value of MRR are 6 A current and 0.4 kg/cm² flushing pressure as well as for the SR the optimized value are 4A current and 1.2 kg/cm² flushing pressure.