Hybrid EMM

Electrolyte circulation can be improved by hybridized EMM with low-frequency tool vibration [5]. It necessitates the development of a suitable microtool vibration system in EMM for effective micromachining operation. Piezoelectric transducer (PZT) can be used for vibrating microtools [6]. Vibration has hydrodynamic effects on the bubble behavior, which has been utilized for the effective removal of sludge, hydrogen bubbles, and the replenishment of fresh electrolyte. The microtool vibrates longitudinally with the definite combination of amplitude of vibration and frequency of vibration. Vibrations within the machining zone, in the stagnant electrolyte, have considerable influence on the diffusion and convection of dissolved metal ions. 

Attempts have been made by the researchers to combine anodic dissolution with other metal removal processes. Hybrid EMM is developed to enhance its dissolution process with higher precision by minimizing above-mentioned limitations by combining the advantageous effects of another process. Some of the hybrid EMM combining anodic dissolution with mechanical grinding, ultrasonic vibrations, magnetic field, EDM, LBM, etc. have been demonstrated to be very successful [14—16]. Few of the attempts undertaken by the researchers have been mentioned hereunder. 

Chapter 7 elaborates various important influencing factors of EMM. Influence of lEG, temperature, concentration, electrolyte flow, and tool feed rate has also been described with the help of large number of practical results. Chapter 8 concentrates on various strategies to improve machining accuracy of EMM. Hybrid EMM teclmiques which are the newer developments to improve the effectiveness of EMM have also been included. Selections of optimal combination of EMM parameters validated by test results have also been incorporated to enhance the machining efficiency and accuracy. Chapter 9 includes numerous practical and industrial applications of EMM. Various factors which restrict the wider usability of this process have been discussed. This Chapter also focuses on how to minimize these adverse factors by applying various remedial measures. 

The basic scheme of hybridization of EMM with micro-EDM (a) Process begins, (b) discharge, (c) dissolution,... 

Schematic diagram containing different stages of EMM hybridized with Laser.

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