烧结金刚石电极放电烧蚀磨削复合加工技术研究

发布时间：2018-05-05 05:13

本文选题：电火花加工 + 雾化烧蚀　；参考：《南京航空航天大学》2017年硕士论文

【摘要】：目前,电火花加工是难加工材料加工的一种主要方法,但是其加工能量受制于脉冲电源,蚀除效率很低。电火花诱导烧蚀是一种新出现的针对难加工材料加工的方法,利用电火花诱导工件活化,并利用氧气与活化区域发生燃烧反应快速蚀除材料,效率得到很大地提高。但是烧蚀反应产生大量氧化物附着在加工表面,无法排出,影响后续放电,从而影响加工效率。为此,本文提出采用烧结金刚石材料作为电极,利用金刚石颗粒在线磨除修整氧化层,促使烧蚀反应持续高效进行。本文从以下几个方面进行了系统的研究:(1)提出了烧结金刚石电极雾化烧蚀磨削复合加工方法,构建了试验系统。现阶段的冲液雾化烧蚀加工会使得反应区域产生氧化层,其电阻率较高,且不易燃烧。采用烧结金刚石电极,电极金属部分放电参与雾化烧蚀,金刚石磨粒在线修整氧化层,保证烧蚀反应高效持续进行。(2)提出了压力作为检测信号的伺服控制方法,设计并搭建了整个系统。具体包括压力采集,信号处理,伺服驱动以及基于LabVIEW的实时采集和监测试验数据的串口通信。实现了PID控制方法,模糊控制方法和反比例控制方法,并进行了对比实验。(3)建立了研究雾化烧蚀磨削复合加工模型。研究发现复合加工过程分为放电诱导,高效烧蚀,磨粒磨削,电极修整四个阶段。(4)开展了模具钢和高强钢的工艺优化试验。并研究了相关参数(峰值电流、脉冲宽度、脉冲间隔、电极转速)对雾化烧蚀磨削复合加工特性的影响规律。对于模具钢,复合加工方法能够进行高效稳定加工,效率是铜电极电火花加工的6.3倍;相比于铜电极的烧蚀加工,效率提升了88%。对于高强钢,复合加工的效率是雾化烧蚀的1.3倍,且复合加工的表面质量要明显好于雾化烧蚀加工的表面。
[Abstract]:At present, EDM is one of the main methods for machining refractory materials, but its processing energy is limited by pulse power supply, and the efficiency of etching is very low. EDM ablation is a new method for machining refractory materials. The efficiency is greatly improved by using EDM to induce the activation of workpieces and to rapidly erode the materials by combustion reaction between oxygen and activation region. However, the ablation reaction produces a large number of oxides attached to the machined surface, which can not be discharged, which affects the subsequent discharge, thus affecting the processing efficiency. In this paper, sintered diamond material is used as electrode, diamond particles are used to grind the oxide layer online, and the ablation reaction is carried out continuously and efficiently. In this paper, a systematic study on the following aspects has been carried out. (1) the method of atomization and ablation grinding of sintered diamond electrodes has been put forward, and the experimental system has been constructed. At the present stage, the oxidation layer is produced in the reaction region by the atomization and ablation of the liquid, and its resistivity is high, and it is not easy to burn. Using sintered diamond electrode, partial discharge of electrode metal to participate in atomization ablation, dressing oxide layer of diamond grain on line, ensuring the ablation reaction to be carried out efficiently and continuously.) the servo control method of pressure as detection signal is put forward. The whole system is designed and built. It includes pressure acquisition, signal processing, servo drive and serial port communication of real time acquisition and monitoring test data based on LabVIEW. The PID control method, fuzzy control method and inverse proportional control method are implemented. It was found that the process of composite machining was divided into four stages: discharge induction, high efficiency ablation, abrasive grinding and electrode dressing. The process optimization tests of die steel and high strength steel were carried out. The influence of parameters (peak current, pulse width, pulse interval, electrode speed) on the characteristics of atomized ablative grinding composite machining was studied. For die steel, the composite machining method can be processed efficiently and stably, and the efficiency is 6.3 times higher than that of copper electrode EDM. Compared with the ablation of copper electrode, the efficiency is increased 88%. For high strength steel, the efficiency of composite processing is 1.3 times that of atomization ablation, and the surface quality of composite processing is obviously better than that of atomized ablated surface.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG661

【参考文献】