Electro chemical grinding

Mechanical Engineering

Electro chemical grinding (ECG):

The Electrochemical grinding (ECG) and Electro-chemical machining (ECM) are similar instead of tool used in Electro-chemical grinding is an abrasive grinding wheel in place of tool. The metal is removed both by Electro-chemical decomposition (90%) and abrasion of the metal (10%). A non corrosive salt solution is used as an electrolyte. It also acts as cutting fluid or coolant. 

The grinding wheel is made cathode (-ve charge) and work piece is made anode (+ve charge). Both the work piece and grinding wheel are electrically conductive. Grinding wheel rotates and is mounted on a spindle. Workpiece is held in a fixture and can be moved in forward and backward direction. Electrolyte is pumped in gap between grinding wheel and workpiece. Current flows from cathode to anode through the electrolyte. This results in chemical oxidation of workpiece. The oxide film formed on work piece is removed by the grinding wheel. It produces an accurate and fine surface. The material removed from work piece is decomposed into electrolyte solution.

In this process metal removal rate is very low and power consumption is high.

It has increased tool life and there is negligible wear of tool so dressing of wheel is not required frequently.

The grinding wheel is a metallic disc embedded with abrasive material. The most commonly used materials are copper, brass and bronze. Aluminum oxide and diamond particles are used as abrasive material.

The grinding wheel and work piece are insulated from rest of the machine.

It is used for precise grinding of hard material like tungsten carbide tool tips.