Choline chloride based ionic liquid - an alternative electrolyte for ECM?

Choline chloride and ethylene glycol (1:2) form a room temperature ionic liquid (RTIL). The authors have investigated the relevant properties of ChCI/EG in view of the application of ionic liquids as alternative electrolytes for ECM. The electrolyte is suitable to machine the valve metal titanium, because the anodic oxide film formation is strongly suppressed. It has been shown that neither the lower conductivity nor the higher viscosity is a relevant handicap for application. The larger electrochemical window in comparison to/with water based electrolytes seems to have no effect for ECM processes because the used voltages are far out of range of the thermodynamic stability of ChCI/EG. It has to be expected that the electrolyte is strongly decomposed during the ECM process. Therefore it seems to be important to investigate the decomposition products. In a first approach it can be said that e.g. Cb is probably not formed.