Novel Electrolytes for the Electrochemical Machining of Air-Breathing Propulsion Materials

The proposed program addresses the exploratory development of an advanced electrochemical machining (ECM) technology which relies for its high performance upon the employment of dispersed microparticles in aqueous electrolytes. The approach will utilize suspended particles of C, Ti, Ag, or zeolite Y incorporating Ag or Ti, in aqueous solution containing the respective supporting electrolytes NaF, NaCl, NaBr, NaClO3, NaBrO3, and NaNO3. These electrolyte mixtures will be used in the ECM of titanium and titanium alloy materials employed in air breathing gas turbine propulsion units. Enhanced ECM performance will result because suspended particles will function as microelectrodes in an applied electric field, while exhibiting microscopic electrical discharge phenomena. This will result in favorably perturbing the local ionic and chemical environments in the presence of microparticles compared to the surrounding medium. The presence of suspended electronically conductive microparticles in the electrolyte is anticipated to mitigate catastrophic spar- king, Joule heating, cathode polarization, and anode shape changes due to these effects. Additionally, it is expected that electrochemically machined surface tolerances will be on the scale of microparticles. The approach is not expected to require significant modification of hardware used with current aqueous electrolyte based electrochemical machining technologies.