Development Of Micro-Arc Oxidation Pulse Power Supply Process Control System

In order to realize the design of micro-arc oxidation process which can change the electrical parameters in real time,this paper adopts Weiluntong touch screen as the display system,and the motherboard with 80C196 KB chip as the core as the power control system,through the TTL to RS232 level module and Modbus communication protocol.Connected to form a micro-arc oxidation power process control system.The touch screen UI design software is used to write the human-computer interaction interface of the system,and the oscilloscope is used to detect the SCR trigger signal and the IGBT drive signal after the online debugging.On this basis,the micro-arc oxidation process was designed to investigate the effects of the output voltage,the power-on time and the turn-off time of the unit pulse on the micro-arc oxidation process.The scanning layer electron microscopy and Image J software were used to analyze the pores of the film layer;the thickness of the film layer was analyzed by using a coating thickness gauge;the corrosion resistance of the film layer was analyzed by using an electrochemical workstation;and the process control process was given according to the analysis result.The design idea is compared with the corrosion resistance of the sample treated under fixed parameters.The research results show that the combination of 80C196 KB chip and Weiluntong touch screen fully meets the requirements of micro-arc oxidation power supply process control system,and can realize real-time process control process control requirements.The Modbus protocol written in assembly language can be well compatible.Weiluntong touch screen.Using the PID algorithm as a voltage loading program,a stable rise and fall of the voltage can be achieved.In the process test,the influence of the voltage value on the surface morphology and corrosion resistance of the film is the largest.With the increase of the output voltage and the increase of the voltage duration,there are obvious differences between the pores and the film thickness on the surface of the film.The combined results show a significant increase in corrosion resistance.Under the same voltage,within the unit pulse,the off time of the fixed power supply is 4mm,which prolongs the turn-on time of the power supply,which can improve the compactness and corrosion resistance of the film.Correspondingly,under the same voltage,the fixed power supply turn-on time is 0.5mm,which prolongs the turn-off time of the power supply,increases the uniformity of the film layer,reduces the thickness of the film layer,and reduces the corrosion resistance of the film layer.In the uniformity of the pores,the thickness of the film has a large influence on the corrosion resistance.Further investigation of the influence of power-on time and turn-off time in the unit pulse on the micro-arc oxide film layer shows that the regularity of the influence of the two on the film layer becomes more significant as the processing voltage rises and continues.Through the above results,the process control process test was designed,and it was found that the corrosion resistance of the sample under process control treatment was better than that under the fixed parameter treatment.