【作者】 郭金全；

【导师】 宋博岩；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 随着电子技术、太空技术、航空宇航技术以及海洋工程技术的发展,出现了许多难加工的材料(如结构陶瓷、金属基复合材料、聚晶金刚石、硬质合金等),这些材料不但具有高硬度、高强度、高耐磨性,而且还具有高熔点,抗腐蚀性强等特点,不但是切削加工,即使采用常规的电火花加工技术,进行此类材料的加工也具有一定的难度。本文全面系统地综述了国内外难加工材料的电火花加工技术的研究现状,特别研究了当今难加工材料电火花加工脉冲电源的发展趋势。在深入研究电火花加工材料去除机理的基础上,分析了影响材料蚀除速度的主要因素,并且以硬质合金为例,研究了材料的物理机械性能对电火花加工效率的影响。针对目前电火花加工难加工材料放电不稳定、效率低的问题,提出了具有放电爆炸力的脉冲电源,并且分析了放电爆炸力的形成以及对电火花加工速度的影响。建立了具有放电爆炸力的脉冲电源的热力学模型,利用有限元的方法对模型进行热力学仿真,并进行了初步的验证性试验。根据放电爆炸力产生的条件和要求,研制了具有放电爆炸力的脉冲电源样机。脉冲电源是由低压回路、高压回路和电容增爆回路构成,并搭建了以CPLD为核心的脉冲发生器。最后通过对比试验,验证了具有放电爆炸力的脉冲电源确实能够实现对难加工材料高效、稳定的加工。更多还原

【Abstract】 Along with the development of Electronics, Space technology and Ocean Engineering, there are many kings of Difficult-to-cut Materials (ex. ceramics, metal matrix composites, polycrystalline diamond, cemented carbide ), witch not only have the characteristic of high hardness, high strength, high wear resistance, but also high melting point, high corrosion resistance. It’s difficult to process by both cutting and edm. The dissertation systemic review the edm present situation for machining Difficult-to-cut Materials, especially the influence of pulse power supply.Based on the insight study on mechanism of material removal of edm , this paper analyzes the main factors of the removal rate. As an example, this paper study cemented carbide to develop the relationship between mechanical properties of material and the removal rate by edm.To the instability of discharge, low efficient in edm processing, the paper proposes a new edm power supply with explosion and analyzes the formation of discharge explosion, especially the influence with the removal rate. The heat transfer model of the discharge has been established and the Thermodynamic Finite Element Analysis has been done. At last there is an experiment to verify the analysis.A new kinds of pulse power supply discharged with explosion is designed based on the study of formation reasons of explosion. The pulse generator is composed of low-voltage loop, high-voltage loop and capacitor loop. And a pulse generator has been built by CPLD.According to the contrast experiments, the pulse power supply with explosion is capable of high speed, stable machining.更多还原