Synchronous compound machining method and special tool for micro-hole EDM-electrolysis in different regions

Abstract

The invention provides a synchronous composite processing method of micro-hole electric sparks and different electrolytic areas and a special tool of the synchronous composite processing method. The synchronous composite processing method includes that a tube electrode is switched to impulse voltage, and a neutral salt solution with ultra-low concentration flows into a processing area via the inner side of the tube electrode at a high speed, and then flows out of the processing area along a gap between the tube electrode and a workpiece; an end face of the tube electrode is subjected to high-speed punch processing with axial feeding of electric sparks under the ultra-low concentration of the neutral salt solution, and a hole wall processed by the electric sparks is subjected to radical electrochemical finishing and machining under the action of low-pressure voltage. By the synchronous composite processing method, processing precision is guaranteed, punching efficiency is improved, and processing requirements on various kinds of holes of an aircraft engine are met. Different from conventional electric spark processing and electrolytic processing, the synchronous composite processing method adopts the neutral salt solution with the ultra-low concentration, so that processing efficiency in electrochemical dissolution can be greatly improved and corrosion degree of equipment can be decreased.

Description

technical field [0001] The invention belongs to the technical field of special processing, in particular to a micro-hole electric spark-electrolysis different-zone synchronous compound processing method and a special tool thereof. Background technique [0002] With the continuous development of the aviation industry, the internal structure of aero-engines is becoming more and more complex, and there are a large number of tiny holes in its key components, especially the film cooling holes of the turbine blades, which are small in diameter, large in number, and complex in distribution. The processing quality of the small hole is high, and there is no recast layer and residual stress. At the same time, the blade is mostly made of difficult-to-machine materials such as cast high-temperature alloys or titanium alloys. Therefore, traditional machining methods are difficult to meet the processing requirements. [0003] In recent years, special processing methods for micro-holes of ...

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Problems solved by technology

[0005] On November 12, 2008, the Chinese patent application number 200710025527.9 disclosed an integrated processing method and device for cutting and texturing solar silicon wafers. The working fluid is based on the combined processing principle of electric spark discharge without cutting force and high-temperature pulse electrochemical corrosion to realize the combined cutting and texturing process of large-scale ultra-thin solar silicon wafers by electric spark discharge and electrolysis, which meets the production process needs of crystalline silicon solar cells, but the The process method is mainly for composite processing of solar silicon wafers, and the wire cutting process is mainly used, which cannot be applied to the hole-making process of difficult-to-machine metal materials

[0006] On February 16, 2011, the Chinese patent application No. 201010289524.9 disclosed an electrolytic EDM composite micromachining device and its processing method. This method utilizes the characteristics of physical contact between the processing electrode and the non-conductive workpiece to be processed, and introduces cutting processing, making it a new electrolytic EDM composite micromachining device, which makes up for the shortcomings of the original electrolytic EDM method in terms of processing efficiency and processing accuracy, and makes it have high material removal rate, high processing accuracy, The surface quality is good, the cost is low, etc., but this method is mainly aimed at the processing of non-metallic materials. Due to the direct contact in the processing process, there is a macroscopic force, so it is not suitable for micro-hole processing of difficult-to-machine metal materials such as high-temperature alloys.

This method mainly aims to solve the problems of processing taper error, poor electrode surface quality and low processing efficiency of the cutting edge electrode micro-electrolytic grinding method in the existing block electrode EDM method. Grinding and finishing combination processing technology, but this process method is mainly aimed at micro electric grinding processing, and cannot be extended to the processing of micro holes

[0009] On April 3, 2013, the Chinese patent application number 201210516567.5 announced a composite processing method for metal materials. This method uses a weak electrolyte aqueous solution as the working fluid, and at the same time uses electric spark discharge and electrochemical action to remove and process metal materials. , the electrochemical cathodic reduction makes the metal ions in the solution electrodeposited on the surface of the tube electrode, which compensates the electrode loss and reduces the electrode loss rate. It is especially suitable for the processing of metal materials with large electrode loss. use, but the invention has low processing efficiency

Wang Yukui of Harbin Institute of Technology and others conducted research on micro-EDM and micro-electrolytic composite milling of three-dimensional metal microstructures. The machining process includes micro-EDM and micro-electrolytic machining. The processing uses the same tube electrode in sequence on the same machine tool, but the Different working media are used. This method is mainly used in milling. Due to the use of different working media, the working fluid needs to be replaced frequently during the processing process, which reduces the processing efficiency.

Professor Zhu Di from Nanjing University of Aeronautics and Astronautics proposed the EDM-electrolytic combined machining process, which organically combines EDM and electrolytic machining, so that EDM and electrolytic machining can be completed under the same machine tool, the same station, and the same tube electrode. Hole making efficiency and quality, but the processing efficiency of this process method is relatively low, and the processing process is prone to short circuit phenomenon, which has a certain impact on the processing success rate

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