Research On EME Machining Process Of Abnormal Deep Hole With Large Length-diameter

With the development of high-performance large-scale weaponry and mechanical equipment,the demand for various deep-hole parts with large aspect ratios and special-shaped cross-sections based on alloy materials is increasing day by day.Aiming at the problems of low efficiency,high cost and poor process stability in the processing of special-shaped deep holes,this paper studies the mechanism of electrofusion blasting,based on deep hole processing machine tools and auxiliary tooling,and combines the development of deep hole processing tool design concepts.For tool electrodes,a process and method of electrical melting and explosion for special-shaped deep holes with large aspect ratios based on traditional deep hole processing technology is proposed.First,the feasibility of processing special-shaped deep holes is analyzed from the basic principles of electrofusion blasting technology,and the mechanism and physical phenomena of material erosion in the process of electrofusion blasting pulse discharge are explored,and the characteristics of electrofusion blasting processing special-shaped deep holes are obtained.And peak current,power supply voltage,electrode material and coolant pressure value affect the more critical process parameters in processing.Then,under the conditions of deep hole processing equipment,auxiliary tooling and special pulse power supply and other facilities,through a single factor experimental method,the changes of the above process parameters on the surface quality and electrode loss of the processing are studied.The results show that:in a certain parameter range Internally,as the peak current increases,the quality of the processed surface becomes worse,and the electrode loss first increases and then decreases;as the power supply voltage increases,the quality of the processed surface and the electrode loss become worse;in the selection of different electrode materials,The surface quality obtained by 45 steel material processing is poor,and the electrode loss is large.The processing surface quality obtained from the copper-tungsten alloy material is better,and the electrode loss is small.The processing surface quality obtained from the copper material is better,and the electrode loss is slightly larger.The melting point,conductivity and other properties of the electrode material are related;as the coolant pressure value increases,the processed surface quality obtained is better,and the electrode loss is small.However,when the coolant pressure value is large,the tool bar will vibrate phenomenon.Secondly,using ANSYS finite element analysis software,through the simulation analysis of the single pulse discharge process of electrofusion blasting special-shaped deep holes,the changes of different electrical parameters on the temperature of the parts and the shape of the material erosion,and the single pulse is derived through the "micro-element method" The volume calculation formula of the down-eroded material overcomes the problem of calculating the work efficiency of the special-shaped deep hole by the electrofusion blasting and provides a basis for the formulation of the processing technology.Thirdly,for the machining objects of special-shaped holes with large aspect ratio,a process plan is proposed to process the circular base hole first,and then perform the electro fusion blasting special-shaped hole processing on the basis of the base hole,and is based on deep hole tool guidance and chip removal.Cooling and other principles have designed and developed a rotary tool electrode suitable for processing special-shaped deep holes.The tool electrode is mainly composed of a rotating part,a body part and a connecting part.Finally,through the method of orthogonal experiment,the significance of the influence of the process parameters such as peak current,power supply voltage,electrode material and coolant pressure value on the surface quality and electrode loss of the machining surface is analyzed,and it is obtained that it is used for large-scale applications under the design conditions.The best combination of process parameters for electrofusion blasting processing of special-shaped deep holes with length-to-diameter ratio is:peak current 120A,power supply voltage 21V,coolant pressure value 6MPa and electrode material is copper-tungsten alloy.