Flow Field Simulation And Experimental Study In Counter-rotating Electrochemical Machining Of Array Convex

Most of the large thin-wall revolving parts,such as casings,have the characteristics of complex structure,uneven wall thickness and difficult to cut materials,etc.Their machining accuracy,machining efficiency and stability have always been the problem of the aviation manufacturing industry.At present,the casings with array structure are becoming more and more common.Traditional cutting is easy to deform the workpiece,and the tool cost is high.Electrochemical machining(ECM)has become one of the conventional means of casing machining in foreign countries because of its advantages,such as not restricted by the hardness of materials,no loss of tools and has high processing efficiency.In this paper,two processing methods are used for revolving metal parts with array convex on the surface.The first one is conventional counter-rotating electrochemical machining(CRECM)which is also known as equal speed CRECM.The second one is called different multiples of speed CRECM.The effects of two processing methods on the forming of array convex were studied.The research content of this paper includes the following aspects:(1)The flow field simulation and optimization of CRECM was carried out.For the two processing methods,the corresponding flow field optimization methods were proposed.For flow field of CRECM,a new method of liquid supply was presented.Under the premise of compressed flow field space,electrolyte flows in from the above and both sides of processing zones,flows out from the below of the processing zone.This method can eliminate the low velocity zone of the processing zone,satisfy the processing requirement.For different multiples of speed CRECM,a better flow field can be obtained by compressing the flow field space.By using the optimized results,the special liquid supply fixtures were designed.The rationality of flow field simulation and fixture design was verified by comparing experiments of the conventional fixture and the new designed special fixture.(2)The forming mechanism of array convex CRECM was investigated.Mathematical model was established to research different parameters.Through ANSYS APDL,electrochemical machining electric field was simulated,researching the influence on forming convex array of different multiples,cathode diameter,height of convex,width of convex,machining parameters such as voltage and inter-electrode gap.In addition,the experiments of CRECM was carried out to study the influence of machining parameters such as different multiples,tool cathode diameter,processing voltage,width of convex,feed depth,feed speed.The experimental results showed that the simulation results werereasonable.(3)The experiment of multiple speed CRECM of array convex was carried out.Based on the study of the first two steps,the structure of the cathode is designed.According to the flow field simulation,a special fixture for the workpiece with a diameter of 200 mm was designed.Finally,the experiment of multiple speed CRECM of array convex is carried out with the designed cathode tool.The experimental results verified the feasibility of multiple speed CRECM.