Basic Research On Forming Law Of Curved Groove In Electrochemical Machining

With the development of modern manufacturing industry in the direction of precision and miniaturization,more and more micro-groove structures have been used in aerospace,precision instruments and biomedical instruments.These groove structures are required to be a certain shape,dimensional accuracy and good surface quality.How to efficiently and stably process groove micro-structures with high accuracy has been an important issue.Electrochemical machining?ECM?is one of the main non-traditional methods,which is based on the principle of electrochemical anodic dissolution.In the machining process of,there is a machining gap between the cathode tool and the workpiece.Theoretically,there is no mechanical loss on the tool cathode,which can effectively reduce machining cost.Workpiece materials are dissolved in the form of ions,which make them have theoretical advantages in machining micro structures,and have great potential in the field of micro manufacturing.The surface quality of the workpiece is good and there is not any residual stress and deformation.This technology can not only efficiently process curved groove structures of various sizes,but also is more suitable for processing curved grooves of difficult-to-machine materials.Based on the theories of hydrodynamics and electrochemical machining,small-sized curved groov structures are taken as the research objects in the thesis.The research emphasis is the forming law of the curved groove in electrochemical machining method.So as to improve the machining stability,machining accuracy and machining velocity of the curved grooves,the distribution rules of the main parameters are researched with the help of FLUENT software.At the same time,the simulation of different cathode feed speeds and different cathode aspect ratios of curved groove structures are also performed.Analyze and study the characteristics of the flow field and the change trend of the flow field in the machining gap of different curved groove structures.The curved grooves machined in electrochemical machining are carried out.And the comparisons and analysis of the stability,machining accuracy and machining velocity of different curved groove structures are studied in situations of various voltages,electrolyte concentrations,cathode feed rates,and cathode aspect ratios.The comparative experiments are carried out between the results with electrolyte adding the Na₄P₂O₇ into the nonlinear electrolyte and with the conventional nonlinear electrolyte.The experimental results show that under the same experimental conditions,the stability of ECM is better with the increase of the angle of curved groove structure.With the increase of the structural angle of the curved groove,the precision of ECM is higher.With the increase of the structural angle of the curved groove,the speed of ECM is faster.With the increase of cathode feed speed,the precision of ECM is higher.With the increase of cathode feed speed,the speed of ECM is faster.However,when the feed speed is too fast,the accuracy and speed of ECM are reduced.With the increase of cathode aspect ratio,the stability of ECM becomes worse.With the increase of cathode aspect ratio,the accuracy of ECM decreases.With the increase of cathode aspect ratio,the speed of ECM becomes slower.The stability,precision and speed of ECM with Na4P2O7 are better than those of conventional ECM.Through the basic research on forming law of curved groove in ECM,the foundation for the future research on the curved cell and the micro machining is established.