The Basic Experimental Study On Micro Ultrasonic Machining For Micro Instruments

With the development of new materials and micro machine, especially new hard and brittle material such as silicon, ceramics, hard metal alloy, the micro machining process technology of these materials is becoming the hot studying spot. Because of the characteristic of USM (Ultrasonic Machining), it is fitter for processing these materials in micro machining field.This paper introduces the recent situations of micro processing technologies and micro USM, the basic principle of USM and the combined technology of USM and ECM(Electrochemical Machining), the particularity of micro USM and the combined technology of micro USM and ECM. The important point of this paper is designing and machining amplitude transformer poles and micro-tools.Two kinds of amplitude transformer pole were designed and machined, exponential shape and stepped shape, and the machining trial demonstrated that the exponential shape is more adapt to micro USM. The most difficult point of the paper is machining micro-tool. Traditional mechanical machining methods can hardly process micro measure structure, then non-traditional machining method can resolve these problems and more easily process 3D(three-dimensional) structure of micro measure and complex shape. Utilizing the advantage of non-traditional machining laboratory, using combinative electric discharge machining method (micro EDM and WEDM etc), several different micro-tools, which can suit for micro USM requests were processed successfully. The result shows that combinative EDM is effective to make micro-tools and processing many kinds of complex 3D micro-structures.The paper introduces simply the characteristics of three experimental materials used to process micro-structures, single-crystal silicon, piezoelectricity ceramic and cemented carbides. Using these amplitude transformer poles and micro-tools, experiments of processing 3D micro-structures by micro USM in three materials were gotten, and good process speed, surface quality and process precision was gained. The results show that micro USM has particular predominance to machining complex 3D micro-structures in hard and brittle materials. In the course of experiment, several special phenomenon was found, the reasons and the settle methods were given. At the end, the further studies on the micro USM and the combined technology...