Electrolyte multiplexing in electrochemical jet processing

Electrolyte design for electrochemical jet processing (EJP) techniques can directly affect form and finish of machined structures. A newly developed, industrially focused, EJP machining centre was designed to incorporate complete control of all relevant machining parameters. A computer numerically controlled, electrolyte multiplexing system, was developed to allow rapid changes in electrolyte type and the ability to mix and fade between electrolytes to create roughing and finishing strategies, and functionally graded surfaces as part of the toolpath program. In this study, the use of three electrolytes (NaNO3, NaCl and a hybrid electrolyte NaI20) are used. Through dynamic electrolyte selection, applied in a sequential manner, it was demonstrated that a combination of NaCl / NaI20 achieved the best compromise of precision and performance, with an increase in depth of 10% over NaI and a 9% kerf reduction over NaCl. Surface finishes were demonstrated to be varied by 40% dependant on the sequence of electrolytes applied without effecting the form. It was shown that graduated surfaces can be created from a high lustre finish to matte by fading electrolyte types. For the first time, an automated method of electrolyte multiplexing is described and the flexibility and process enhancements that can be imparted by this methodology are demonstrated