Study On Mechanism And Experiment Of ELID Grinding Based On Nozzle Electrolysis

In recent years, with the rapid development of optoelectronic information, MEMS, biology and medicine, there exists obvious trend of miniaturization and micromation on products. Cemented carbide materials have been widely used in these products because of their excellent mechanical properties. A typical application is high precision cemented carbide mold for manufacturing micro aspheric lens on the optoelectronic industry. So, research and development of ultra-precision machining technology and equipment for micro aspheric of cemented carbides has important theoretical significance and engineering application value.ELID (Electrolytic In-process Dressing) mirror grinding is suitable for high efficiency and ultra precision machining of cemented carbides. But there also exist some problems on machining micro aspheric, such as difficulties for electrode setup, interference between electrode and workpiece, wear of wheel rod, and wheel vibration. Using nozzle electrolytic ELID grinding, it is no need to install electrode on machining area and above problems can be avoided. Supported by National Natural Science Foundation of China (No.50675064), National High Technology Research and Development Program of China (No.2006AA42335), National Science and Technology Major Projects (No.2010ZX04001-151), International Science&Technology Cooperation Program of China (No.2012DFG70640), this paper mainly focused on this technique, and research of the paper were carried out from basic, process and application research. Through fundamental experiments and theoretical analysis, it attempted to analyze systematically for electrolytic mechanism, technological rule and application of nozzle type ELID.Where, basic research focused on electrolytic mechanism of nozzle electrolytic ELID. Through analyzing and summarizing generation process and action mechanism of oxide film, film thickness models under different electrode materials and connection modes were established. Calculated values of thickness models were compared with measured ones, and their changes basically corresponded with rules of actual film generation.Process research focused on surface grinding of nozzle type ELID, and research were carried out from the perspectives of single and multiple factors. Single factor research was used for summarizing technological rule and laying a foundation for followed multiple factors research and application research. Multiple factors research was used for dominant factors analysis, process parameters optimization and prediction based on orthogonal experiment results and grey system theory. Using grey correlation analysis method, influence degree of different parameters on grinding force and surface roughness were determined. Using grey decision method, optimal combination of the parameters under certain conditions was obtained, and parameter optimization was realized. Using grey prediction method, grey multivariable combination models of grinding force and surface roughness were established and compared with traditional multiple linear regression model. The prediction effect and accuracy were also verified.Application research focused on the development of compound machine tool using nozzle electrolytic ELID and machining of micro aspheric. The former included overall design and key parts development of machine tool. Combined with ultra precision inclined mirror grinding, the latter carried out machining experiments of micro and aspheric surface using developed machine tool. Experimental results under different conditions were also analyzed and summarized.The research about formation mechanism and thickness models of oxide film, process parameters study, compound machine tool development, and micro aspheric machining provided theoretical and experimental basis for efficient, ultra-precision, high quality and low damage mirror machining of cemented carbide microstructures. Meanwhile, it had some theoretical and engineering value for the requirements of ultra-precision micro aspheric mold on photoelectric, optical and information industry, and development of ultra-precision, nano machining technologies and their equipments.