Study On The Control And Process Analysis Of The Tube Inner Wall Spraying With Constrained Electrical Explosion Spraying

Electric explosion spraying is a kind of thermal spraying.It is a new material surface modification treatment,maintenance and manufacturing method based on the application of the electrical explosion phenomenon of conductors.Compared with the traditional thermal spraying method,it has the advantages of low cost,environmental friendliness,spraying of high melting point materials,and convenient adjustment of process parameters.It is especially suitable for preparing coatings for the inner wall of pipe holes.However,according to the current research,the spraying efficiency and coating quality of the inner wall spraying of the constrained electric explosive tube cannot meet the actual industrial production demand,and the method is still in the laboratory research stage.Therefore,this study is devoted to promoting the method of inner wall spraying of the constrained electric explosive tube to the practical application.A set of automation equipment which can perform electric explosion spraying on the inner wall of a small-caliber long pipe with different types of spraying materials?silk,powder,metal foil,etc.?was developed by the understanding of constrained electric explosion spraying.In response to the problems of complicated wiring and difficult function modification of traditional relay control systems,a PLC-based Explosion tube inner wall spray control system was designed.According to the working process of spraying the inner wall of the electric explosion tube,the control target was determined,and the electrical schematic diagram of the spraying control system of the inner wall of the electric explosion tube was designed.According to the parameters of the related control devices,the inner wall spray control system of the electric explosion tube was set up,and the PLC was programmed to enable the spray device to continuously and automatically spray the coatings with overlapping requirements on the inner wall of the tube.In the process of electric explosion spraying,electrical parameter s have a very important impact on the quality of spraying.When the deposition energy on the spraying material can fully heat and melt the material,a uniform and dense coating can be obtained.In this paper,the influence of electrical parameters on the e lectric explosion process of metal wires is studied by means of circuit simulation.The simulation results show that the deposition energy of the wire can be increased and the spraying quality can be improved by increasing the charging voltage and reducing the inductance of the wire.The method of experimental exploration was used to compare the similarities and differences between the electric explosion of metal wire and powder,and the two forms of current waveform and the current introduction mechanism of powder conductor were analyzed.It is proposed that the method of reducing the resistance of the powder system can be used to suppress the generation of bypass current during the electric explosion of the powder,so that the powder is fully heated and melted,and the coating quality is improved.The electrical explosion spraying experiment of Ti₃SiC₂ powder was carried out by using the above-designed spraying equipment for the inner wall of the electrical explosion tube.The according voltage and current waveforms during the experiment were collected at the same time by a voltage divider of Tektronix P6015A probe and a self-integrating Rogowski coil of Person 101 respectively.Effects of the applied voltage,different diameters and the coating quality of Ti₃SiC₂ powder on the electrical explosion and energy deposition were analyzed by means of the SEM results and waveform analysis.A method that adds a certain amount of graphite powder into Ti₃SiC₂ powder was proposed to improve the electrical conductivity and the deposition energy of powder.The research is of practical significance in guiding the development of Ti₃SiC₂ powder coating and broadening the industrial application of high-melting metal powders.