The Development Of The Electro-Spark Deposition Repair Instrument

Electro-spark deposition (ESD) technology is an enhanced processing technology for metal surface treatment,and an important means for processing the metal anti-corrosion and damage repair.Because of its advantages like processing flexible and simple, environmental protection, low-cost and low-loss,the ESD technology has been got more and more applications.First, the paper describes the ESD technology research status of domestic and abroad, analyzes the discharge principle and main factors affecting discharge, discusses ESD repair instrument design and implementation, designs the structure and working principle of pulse power.The ESD repair instrument is divided into three modules including the main circuit,control circuit and auxiliary circuit according to different functions, designed and selected in great detail. The main circuit includes charge-discharge circuit and rectifier-inverter circuit.The charge-discharge circuit provides pulsed current for ESD operation, using independent pulse control mode. The rectifier-inverter circuit charge the capacitor, using full-bridge inverter and full-wave rectifier topology.The auxiliary circuit includes auxiliary power supply circuit, electrode driving circuit and protection circuit with gas. The auxiliary power supply circuit provides power for chips, using flyback circuit topology.The electrode driving circuit drives motor in electrode, using BUCK topology. The protection circuit with gas provides protective gas for ESD operation. The control circuit,whose core is MSP430F149,could set and display Output-voltage value,discharge pulse period and pulse width, speed of the electrode and other parameters through human-computer interaction.It also has the function of real-time monitoring operating status of system.The paper simulinks the main circuit on the basis of the completion of design, and the simulation results are consistent with the theoretical design.Then The control circuit, auxiliary circuit and protection circuit are designed,assembled and debugged with the main circuit together. The debugging results show that the theoretical design, simulation results and debugging results achieve basic agreement. Finally, the prototype instrument is tested, and the test results show that the program designed has good repair effects on the surface repairment,but has some deficiencies like discharging energy lackly and depositing slowly.The paper proposes upgrade programs of ESD repair instrument for existing deficiencies. The upgrades include:enhancing the power of the pulse, increasing the power of pulse power supply from lkW to4kW,changing pulse discharge mode from semi-controlled to full-controlled using MOSFET, achieving the goal of double-loop control of voltage and current replaced TL494with MSP430.Finally, assemble and debug the ESD repair instrument on the basis of the upgrade program. The test results show that the upgrade program has good repair effects on the surface repairmen equally, has some advantages like discharging energy sufficiently and depositing speedly,and can meet most of the requirements of ESD conditions.