Experimental study on developed electrochemical micro machining of hybrid MMC

Abstract

An electrochemical micro machining (ECMM) set-up has been developed and utilized for experiments. The effects ofECMM parameters on material removal rate and electrode wear rate have been analyzed during micro drilling of hybridAl/(Al2O3p+SiCp+Cp)-MMC with tungsten electrode of diameter 298 μm. The machined surface texture, and decompositionof metallic compounds deposited on the workpiece as well as on micro tool have been analysed through SEM, EDX andXRD images. It may occur due to the reaction of the anode with electrolyte (NaCl). The formation of a new compoundsodalite has been identified. This is due to the reaction between sodium chloride and reinforced particles i.e. Al2O3, SiC, Celements presence in hybrid MMC. It has also been identified that the formation of ferropargasite chlorous compound mightbe due to a chemical dissolution of ferrous material and reaction with sodium chloride. Formation of voids, micro-cracks,craters, debris, pulled out materials and pockmarks have been analyzed during micro machining at high current and pulse-ontime parametric setting. From EDX analysis, it has been noticed that the reinforced particles present in hybrid metal matrixcomposite have been deposited on a micro tool. This is due to the melting and re-solidification of hybrid Al/MMC duringmachining by micro sparking at high supply voltage and pulse on time.