Electrochemical Grinding

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Electrochemical Grinding

Theory and Application

Fredy Kuster1 and Mohammad Dalaee2 1 Institut für Werkzeugmaschinen und Fertigung (IWF), ETH Zürich, Zürich, Switzerland 2 inspire AG, Zürich, Switzerland

In ECG processes, schematically shown in Fig. 1, the rotating grinding wheel acts as cathode (negatively charged) which provides the desired shape of the workpiece. The workpiece is connected to the positive pole of a DC power supply. The electrolyte fluid, such as sodium chloride, sodium nitrate, potassium nitrate, etc., is flushed into the small gap between the grinding wheel and workpiece. By applying low voltage of about 4–8 V across the anode and cathode, McGeough (1988) found a high electrical current density of about 120–240 A/cm2 in the gap filled with electrolyte between conductive part of the grinding wheel and workpiece. It constitutes an electrochemical cell in the machining area. The workpiece material is removed by anodic dissolution, an electrolytic phenomenon, but also through a mechanical abrasion mechanism. The major material removal takes place by an anodic dissolution (nearly 90%) and the rest by the mechanical cut of the abrasive grains in the grinding wheel (Benedict 1987). The small chips removed from the workpiece by the mechanical interaction between grains and workpiece stay in the electrolyte fluid as long as they are not further filtered out. The material removal rate of the ECG process is typically at 1600 mm3/min per 1000A and therefore higher than by conventional grinding (McGeough 1988). The grinding wheel profile is the negative of the desired workpiece shape. ECG needs electric conductive grinding wheels as

Synonyms Abrasive electrochemical grinding (AECG); Electrolytic grinding

Definition Electrochemical grinding (ECG) is a hybrid process combining grinding and ECM, which uses a grinding wheel as electrode to remove electrically conductive material. Direct current (DC) flows through an electrolyte between the negatively charged grinding wheel and the positively charged workpiece. Material removal takes place through the combination of mechanical and electrochemical processes, acting on the same area at the workpiece. Advantages of this hybrid machining process result from interaction between microcutting and electrochemical dissolving, both processes acting in a surface layer of the workpiece.

# CIRP 2016 The International Academy for Production Engineering et al. (eds.), CIRP Encyclopedia of Production Engineering, DOI 10.1007/978-3-642-35950-7_16826-1

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Electrochemical Grinding

Electrochemical Grinding, Fig. 1 Schematic setup of electrochemical grinding process

metallic bonding agent, such as copper, brass, or nickel with embedded abrasive particles such as aluminum oxide, CBN, or diamond. In the ECG process, the grinding wheel slightly touches the workpiece. Carbon brushes can be applied to provide the contact between the electrically isolated grinding wheel and the negative pole of the DC power supply. The electrolytic fluid is supplied to the grinding wheel near the workpie

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