【作者】 吴彦春；

【导师】 常志华； 黄尚宇；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2007， 博士

【摘要】 陶瓷制品的坯体成型是制备功能陶瓷材料的一个重要环节，成型方法的好坏直接影响功能陶瓷材料制品的各项性能指标，对于降低功能陶瓷制品制造成本具有十分重要的意义。功能陶瓷粉末低电压电磁压制是本课题组在深入分析国内外功能陶瓷粉末烧结成形及粉末材料压制的研究现状，总结我校多年来在功能陶瓷、电磁成形设备及工艺、粉末电磁压制成形研究经验的基础上提出的融电学、力学、粉末冶金及材料科学于一体的、功能材料成形加工新方法。本文针对低电压电磁压机研制过程中的关键性技术问题开展了一系列的系统研究，在国内外，首次提出运用电荷泵原理和单片机嵌入式开发平台的概念设计电磁压机电源，免去了笨重的工频升压变压器，提高了放电电压的控制精度，有利于准确设定功能陶瓷压制成型工艺参数。利用所设计的电磁压机电源的新特点实现了电磁压机储能电容充电初期的近稳流充电，免去了采用传统稳流电源可能带来的高成本、难维护的问题。作者将状态空间平均法小信号模型用于研究PWM信号对电磁压机电源输出性能的影响，推导出与之相应的状态空间方程，为电磁压机电源的近稳流控制找到了理论依据，并借助计算机仿真实现电磁压机电源设计的元件参数选取。根据电磁压机的特点，依据相关理论，提出了电磁压机的计算机控制方案。将研制的电磁压机用于功能陶瓷的成型压制，系统地考察了放电线圈匝数、放大器锥角、放电电压、二次放电压制对粉末压坯致密度的影响规律，深入分析了电磁压制的机理，为进一步完善电磁压机在功能陶瓷生坯压制上的应用奠定了基础。最后使用所开发的电磁压机压制在现代功能陶瓷中占有很重要地位的压电陶瓷粉末，通过对压电陶瓷压坯及制品的致密度、显微结构的深入分析研究，确定电磁压制参数对功能陶瓷性能的影响，研究表明电磁压制优于传统静压干压法，能显著提高功能陶瓷制品的各项性能指标。更多还原

【Abstract】 Ceramic clay body forming has been an important key in function ceramicmaterials producing. It has been very important that the stand or fall of forming forfunction ceramic can affect all kind of the function ceramic’s performances.Low-voltage electromagnetic compaction of function ceramic powder waslodged by the study group for the first time through researching the status in quo ofstudying in the sintering function ceramic powder and compaction of powdermaterials, and summed up our school’s researching on the function ceramics,electromagnetic forming equipments, powder metallurgy, and so on. It is a newmethod for function materials forming, which has inosculated electricity, mechanics,powder metallurgy and material science.In this paper, the author has done series researches on the key technologies of thelow-voltage electromagnetic compaction machine. The idea was lodged firstly in theworld, which use the principle of charge-pump and the development platform ofembedded applications based on SCM in the design of the low-voltage electromagneticcompaction machine’s power. In the results, the heavy transformer has beenabnegated. The control precision of discharge voltage has been improved. Thecurrent-limiting-analogous charge has been come true.The author has studied the effect of the power’s output by PWM signal with thestate-space average model. The state-space average equations was calculated, and selected theparameter of the power’s components with computer simulation. The theory ofapproximately steady current control was lodged.The control project is lodged by computer with correlative theories.Through the study on powder compaction experiment, and analyzed therelationship between the total number of the loop, the amplifier’s cone angle, thedischarge voltage, second compaction and the density of the ceramics.Lastly, the low-voltage electromagnetic compaction machine was used tocompact the piezoelectricity ceramics powder for study the compaction effects bydifferent compaction parameters and proved the electromagnetic compaction is betterthan pressed-green.更多还原