Research On Shaped Regular Pattern Of Electrochemical Machining For Irregular Cavity

Integral component with compact structure, high strength and light weight is an important part of aerospace engine. But the structure of closed Integral component being very complex, its vortex paths (irregular cavity) between blades being narrow and twisting, the material hard and machinability poor, processing the closed Integral component have become a difficult manufacturing problems in the world.Combining the NC electrochemical machining (ECM) and electrolytic discharge (EDM) is a great demand subject in recent years. A scheme of ECM digging with aping simultaneously is presented in this paper to enhance the efficiency of ECM further. Simulating machining gap flow field for the condition of forward flow and reverse flow type were processed based COMSOL software which determined the design with the reverse flow type fixture of ECM. Relationship of these function such as positioning, sealing, diversion and conducting were studied, and the diversion structure was improved by finite element analysis based installation and adjusting the fixture for ECM.These experiments processing the three closed Integral component, the materials of which are CrWMn、40Cr、S-03 stainless steel respectively, were carried out one by one in NaCl, NaNO3、NaClO3 and its compound electrolyte.The electrolyte prescription appropriate to above three materials were studied, the relationship between machining gap and voltage, machining gap and feed rate, which is concerned with the shaped regular pattern on digging with shaping ECM simultaneously, were discussed.Detecting these vortex paths of closed Integral component processed every time, finding the error value between the size processed and blueprint, we modified shape of the cathode, so that the subsequent machining allowance turn into smaller.Three composite electrolyte prescriptions for above materials of the closed Integral component——5%NaCl+16%NaNO3+4%NaClO3,10%NaCl+16%NaNO3+2%NaClO3 and 18%NaNO3+7.5%NaClO3——were determined separately by experiments. The shaped regular pattern were discussed, which indicate that the machining gap increases with the raise of voltage under the condition of same electrolyte pressure, concentration, feed rate, and decrease with the increase of feed rate under the condition of same electrolyte pressure, concentration, voltage. The processing specimens are tested by the three-coordinate measuring instrument of professional factory, the dimensional accuracy conform to the requirements. The research shows that the reverse flow type is better than the forward flow type for the closed integral structure by ECM; different material must be compatible with the appropriate electrolyte, process parameters; and the scheme of digging with shaping ECM simultaneously is an effective ECM means for the vortex paths of the closed Integral componentthe; the efficiency of ECM has increased 80% than EDM.