Experimental investigations into rotary mode electrochemical discharge drilling (RM-ECDD) of metal matrix composites

Abstract

In the present work, rotary mode electrochemical discharge drilling (RM-ECDD) was employed to machine the Al-6063 SiC_p metal matrix composites (MMC’s). The effect of various process parameters such as applied voltage, pulse on time, tool rotation rate, electrolyte concentration and current on quality characteristics (hole over cut and depth of penetration) of the drilled holes was investigated. The underlying material removal mechanism during the machining of MMC’s with RM-ECDD is also proposed by considering the scanning electron micrographs (SEM) and simulation results as an evidences. A comparative analysis between RM-ECDD and ECDD was performed during the machining of MMC’s. The experimental results reveal that the integration of tool rotations in ECDD successfully evacuates the sludge/debris from the machining zone, and it also replenishes the electrolyte effectively. Therefore the use of RM-ECDD improves the aspect ratio (L/D), and it exhibits 23.07 times higher L/D ratio than the ECDD process. In ECDM, the discharge characteristics are very important outcome that explores the significant details of the involved mechanisms and phenomena of the process. In the present research, a DSO recorded voltage signals were used to understand the discharge behavior and their characteristics at different parameter combinations. This paper also presents a second-order mathematical models to determine the relation between input process parameters and quality characteristics. Desirability based multi objective optimization approach was employed to optimize the process parameters.

Keywords:

• Discharge characteristics
• ECDM
• machining of MMC’s
• L/D ratio
• material removal mechanism
• modeling
• optimization
• rotary mode ECDD