Study On Electrochemical Machining Technology Of Aircraft Landing Gear Deep Hole

Aircraft landing gear as the key bearing component of aircraft take-off?landing and ground sliding,by virtue of its complex internal cavity special-shaped hole structure,through absorption and Dissipating the impact energy formed between the landing and sliding of the aircraft and the ground ensures,the flight safety performance is guaranteed,and in order to make these special-shaped supporting holes have excellent material mechanical properties,At present,the mainstream landing gear special-shaped holes are made of 300 M steel with ultra-high strength and toughness.However,when using traditional machining manufacturing such hole,special-shaped structure due to the complexity of material type high strength characteristics and pore structure,make this kind of hole in cutting process is due to stress,high cutting temperature,cutting chip removal and cooling impeded caused the phenomenon of blade,tool wear and serious crack may make it harder for the cemented carbide materials complex profile hole to mass rapid manufacturing implementation in a relatively short period.To this end,this paper USES the advantages of electrochemical machining,which has the advantages of non-contact machining of complex special-shaped and difficult cutting materials,to propose an electrochemical machining technology based on the study and analysis of the micro-electrochemical removal mechanism of 300 M steel aircraft landing gear special-shaped hole.Firstly,in terms of flow field mechanism research,according to the electrochemical gas-liquid two-phase flow theory,the flow parameters such as bubble rate,section gas-holdup and flow density were introduced to construct the gas-liquid two-phase flow mathematical model of electrochemical machining,and the numerical calculation was used to guide the design of cathode flow passage structure based on flow field design parameters.Secondly,according to the electrochemical electrode process and Faradayundefineds law,the electric field models in the environment of primary,secondary and tertiary current density are established in the research of electric field mechanism,and the erosion velocity model is obtained by COMSOL simulation analysis.At the same time,based on the analysis of the action mechanism on the electric field and flow field,the finite element analysis model of multiple physical field coupling is established,and the effect of the process parameters on the machining quality and efficiency under the coupling action of the multi-physical field is studied.The optimal process design parameters are obtained by using stepwise regression analysis and comprehensive error evaluation criteria,so as to realize the optimal design of macro-process.Finally,in order to verify the accuracy of the parameters based on the multi-field coupling model,the electrochemical machining experiments were carried out on the landing gear cavity according to the optimal parameters obtained,and high-precision landing gear parts were obtained.By studying the microcosmic corrosion mechanism of 300 M steel in the environment of electrochemical machining,the coupling model of multi-physical field is established from the two key physical fields of electric field and flow field,which are the two key physical fields: electric field and flow field.In order to realize the high precision and rapid manufacture of complex special-shaped holes of 300 M steel landing gear,the macro-designer can guide the micro-electrochemical corrosion removal characteristics.