This article proposes a precise and ecofriendly micromachining technology for aerospace application called electrochemical machining in pure water （PW-ECM）. On the basis of the principles of water dissociation, a series of test setups and tests are devised and performed under different conditions. These tests explain the need for technological conditions realizing PW-ECM, and further explore the technological principles. The results from the tests demonstrate a successful removal of electrolytic slime by means of ultrasonic vibration of the workpiece. To ensure the stability and reliability of PW-ECM process, a new combined machining method of PW-ECM assisted with ultrasonic vibration （PW-ECM/USV） is devised. Trilateral and square cavities and holes as well as a group of English alphabets are worked out on a stainless steel plate. It is confirmed that PW-ECM will be probably an efficient new aviation precision machining method.
In order to develop green manufacturing and microfabrication,an innovative electrochemical machining method was introduced,that is the electrochemical machining(ECM)technology in ultra-pure water.The relative relationship of water dissociation and current density under the function of strong acid cation exchange membrane was studied,and the mechanism of electrochemical machining in ultra-pure water was also explored.On the basis of theoretical analysis,the significance of two turning points of the voltage-current density characteristic curve was presented.As the result of water dissociation and machining experiments,the factors affecting current density were determined.
