Reasearch On Electric Spark Atomization Ablation Machining Deep Abnormity Cavity

With the improvement of aero engine performance,new-generation engines are increasingly using internal components with complex shaped channel structures.These components are difficult to process due to their complex geometry,large cavity depth,and the use of high-temperature alloys and titanium alloys.The characteristics of the material make the overall manufacturing difficult.The dischargeinduced controlled ablation processing technology has the characteristics of high processing efficiency,small tool electrode loss,and green economic processing,which is very suitable for the molding processing of difficult-to-machine materials.This paper applies aerosol medium to EDM induced ablation processing technology,and proposes the use of atomized ablation forming processing technology for deep and narrow special-shaped cavity processing of difficult-to-machine materials nickel-based superalloys.The special-shaped channel is the processing object,which mainly does the following work:(1)A closed-loop atomizing medium supply device capable of maintaining a stable and controllable atomizing medium supply for a long time is designed and constructed for experimental research and cavity processing.(2)Theoretical analysis of the breakdown principle of the atomized medium,the macroscopic processing principle of the atomized ablation,and the chip removal mechanism of the atomized ablation,and the comparative analysis and experimental verification with the traditional flushing electric discharge machining method,confirming the atomization burning Etching has the characteristics of stable state,high processing efficiency and good chip removal effect.Contrast tests of atomized ablation processing,atomized air medium processing and traditional flushing electric discharge machining were performed.The processing effects of the three processing methods were analyzed,and it was confirmed that atomized ablation processing had processing efficiency,processing accuracy,and electrode loss.Aspect has advantages.(3)Using multiple processing parameters,experimental analysis and optimization of processing parameters of the atomization and ablation processing of nickel-based superalloy GH4169 were performed,and deep holes with a depth-to-diameter ratio of GH4169 of more than 25 were achieved using the preferred processing parameters.machining.(4)Computational fluid dynamics(CFD)was used to simulate the analysis of the inter-electrode medium distribution and chip removal of the special-shaped electrode processing.The results show that the atomization ablation process is suitable for the variable-shaped special-shaped holes and specialshaped cavities.The chip removal effect is better than that of conventional cavity machining.The simulation results verify the rationality of the simulation results.(5)It is verified through a comparative experiment that the discharge-induced atomization ablation processing method can meet the requirements for efficient processing of deep special-shaped cavities.Aiming at the problem that the inter-electrode state of atomization ablation processing sharply deteriorates after the processing depth of the special-shaped cavity is increased,the analysis of Segment atomization and ablation forming processing method.The flow field and particle motion trajectory between direct electrode processing and segmented electrode processing were simulated and compared.Based on the simulation results,a segmented machining test was carried out to verify,and a deepshaped cavity and deep tapered hole prototype of superalloy GH4169 were fabricated.(6)The design of the trimming processing scheme has achieved the high-temperature alloy GH4169 special-shaped cavity prototype that meets the processing quality requirements.The actual processed cavity outlet size is 26 mm × 10.8mm,the inlet size is ?4.4mm,and the cavity depth is67.5mm.Surface roughness Ra6.0.