【作者】 冯欣荣；

【导师】 吴汉华；

【作者基本信息】 吉林大学 ， 测试计量技术及仪器， 2004， 硕士

【摘要】 微弧氧化是一种直接在阀金属及其合金表面原位生长陶瓷层的新技术，它通过阀金属（Al，Ti，Mg，Hf等）在电解液中进行等离子体放电，产生复杂的电化学、热化学、等离子体化学反应，在阀金属及合金的表面形成一层坚硬、致密的氧化陶瓷膜。这种氧化膜具有显微硬度高，耐磨性好，与基体的结合力强，耐腐蚀等优点，因而在机械、汽车、国防、电子、航空航天和建筑民用等工业领域具有重要的潜在应用价值。微弧氧化装置包括专用高压电源、氧化槽、冷却系统和搅拌系统。本文介绍了多功能微弧氧化专用高压电源的研制。微弧氧化一般在恒流或恒压方式下去研究阀金属表面所生成的氧化陶瓷膜性能。目前，从事微弧氧化研究的工作者所采用的电源，虽然也能在恒流或者恒压下工作，但是这些电源所能提供的工作电流或者电压的频率为工频，波形和脉宽不可选择，这就大大限制了所制备的氧化陶瓷膜的性能。本文介绍的微弧氧化电源能对工作电压或电流的频率和脉宽在较大范围内进行连续调节，工作电压或电流的脉宽和频率等多种电参量可实时数字显示，同时，该电源可通过串行口与上位机相连，以便实时记录多种电参数在工作过程中随时间的变化规律，为探索制备具有优良特性的微弧氧化陶瓷膜的工艺条件提供有力的工具。论文主要从硬件结构和软件结构两方面介绍这种多功能微弧氧化电源。电源硬件结构主要包括主回路和控制电路两部分。主回路主要由IGBT、电压调节电路、滤波整流电路、IGBT的吸收电路和驱动电路组成，其中电压调节电路使阴、阳极电压值在0~±1000V范围内单独、连续可调，IGBT的吸收电路是用来控制IGBT关断和续流二极管恢复时产生的尖峰电压，以防止IGBT的损坏，IGBT的驱动电路用来控制IGBT的关断或导通。 控制电路部分以单片机为核心，其外围电路包括数据采集电路，<WP=76>脉宽调制电路，波形选择电路，电机控制电路，键盘、指示灯和显示接口电路及串行通讯接口电路。电源选用ATMEL公司生产的AT89C52作为微处理器；数据采集电路完成对阴、阳极电压值，阴、阳极电流值等四路数据的采集及进行模/数转换；脉宽调制电路为IGBT提供驱动信号，这个驱动信号同时提供给单片机计数器T1，以获得脉冲宽度和频率值，适当选择电路中电位器的值就可实现脉冲频率在20Hz~10KHz范围内连续可调、脉冲宽度的占空比为10%~90%；波形选择电路通过程序控制实现交流、脉冲、正向直流及反向直流等电压波形的选择；电机控制电路控制主回路中三相调压器的正反转和停止启动；键盘、指示灯和显示接口电路选用了8155和8279，8155主要完成对按键和指示灯的控制，8279主要完成对阴、阳极电压值，阴、阳极电流值，脉冲宽度和频率的显示控制；串行通信接口电路选用的是低功耗的MAX232，完成TTL－RS232电平的转换，实现电源与上位机的通信。系统软件包括计算机控制程序和电源监控程序两部分。计算机控制程序采用VB语言编写而成，电源监控程序部分采用汇编语言编写而成。第三章主要介绍了计算机监控程序和电源监控程序中主程序和子程序的流程图。这台多功能微弧氧化电源完成了预期的设计要求，将为进行微弧氧化研究的工作者提供有力的工具。更多还原

【Abstract】 Microarc oxidation (MAO), a new technology, can directly form oxide ceramic coatings on the surface of the valve metals such as aluminum, titanium, magnesium, hafnium etc. or their alloys. By the plasma discharging of the valve metals in an aqueous electrolyte solution, MAO produces complicated reaction including electrochemistry, hot chemistry and plasma chemistry, and it forms a hard and compact oxide ceramic coating on the surface of the valve metals and their alloys. Due to the oxide coating having many virtues such as high microhardness, good wearlessness, strong binding force with the matrixes, erosion resistance etc., MAO is extensively applied in the fields of mechanism, automobile, national defence, electronics, aviation, architecture and so on.The microarc oxidation equipment includes special high-voltage power-supply, oxide groove, cooling system and churn-dasher. This thesis introduces the research of high-voltage power-supply.MAO usually researches the properties of the oxide ceramic coatings in the mode of constant voltage or constant current. Now the power-supplies that are adopted by the persons who are engaged in this research can work in the mode of constant voltage or constant current, but the frequency of the working current and voltage they provide is only 50Hz, and the waveform and the pulse width cannot be chosen. Those restrict the properties of the oxide ceramic coating. The power-supply mentioned in this thesis can continuously adjust the frequency of the working voltage and current in the larger range, and can choose the waveform and the pulse width. The power-supply displays many electric parameters in digital, meanwhile it can record the change of the parameters by the upper computer. This thesis mainly introduces the hardware components and software <WP=78>framework of the multifunction microarc oxidation power-supply. Hardware components include the major loop and the control circuit. The major loop is composed of IGBT, voltage regulation circuit, commutate and filter circuit, snubber and drive circuit. The function of the voltage regulation circuit is to solely and continuously adjust cathode voltage and anode voltage in the range of 0~±1000V. Snubber controls the spike voltage as the IGBT turns off and the diode resumes to prevent the IGBT from being damaged. Drive circuit controls turnoff and ducting of the IGBT. The control circuit takes the singlechip computer as the nucleus, its peripheric circuits include data acquisition circuit, pulse width adjusting circuit, waveform chosen circuit, electric machinery circuit and interface circuit. The power-supply chooses AT89C52 as the microprocessor. The data acquisition circuit gathers four data, namely the values of cathode voltage, anode voltage, cathode current and anode current. The pulse width adjusting circuit provides the drive signal to IGBT. The drive signal is conveyed to counter T1 for the values of frequency and pulse width. We may realize that the frequency continuously adjusts in the range of 20Hz~10KHz and ratio of the pulse width is 10%~90% by choosing the proper the value of the potentiometer. The waveform chosen circuit can realize the chosen of the voltage waveform such as AC, pulse, DC etc. by the control of the program. The electric machinery circuit controls the corotation, reversal, startup and suspend of the three-phase booster in the major loop. The interface circuit mainly includes the interface of the keyboard, the indicator light, display and communication. The main components in the interface circuit are 8155, 8279 and MAX232. 8155 controls the keyboard and the indicator light. 8279 controls the display of the electrical parameter. MAX232 changes TTL into RS-232 in order to communicate between the power-supply and the upper computer.Software framework of the power-supply consisted of computer <WP=79>monitoring program and power-supply monitoring program. The monitoring program was respectively compiled in VB and assemble language. Chapter three mainly introduces the program flow chart.The multi更多还原