钛合金深小孔精微电火花加工工艺研究

对钛合金深小孔的电火花加工工艺进行了深入的研究。优选了电火花加工放电参数;应用了超声复合和削边电极等工艺手段。通过研究,极大地提高了加工速度和加工质量。     

SiC_p/Al高速电弧放电加工研究

研究了高速电弧放电加工铝基碳化硅增强复合材料(Si Cp/Al)的性能。通过对体积分数为20%的碳化硅颗粒增强铝基复合材料进行加工实验得出:在峰值电流500 A、脉冲宽度10 ms时,材料去除率超过8200 mm3/min,电极损耗率约为2%。此外,研究了加工极性对工件表面质量的影响,得出电极负极性、大电流可用于大余量材料去除,电极正极性、小电流可用于小余量表面修整的结论。最后,采用高速电弧放电加工实现了碳化硅颗粒增强铝基复合材料的钻孔、铣削和切割等加工工艺。     

复杂流道构件组合放电加工技术研究

复杂流道构件的高效、高精度加工是液体火箭发动机的核心制造技术之一,随着发动机涡轮泵功率及涡轮效率的不断提升,涡轮泵复杂流道构件的加工去除量大幅增加,同时对加工精度的要求也越来越严格。故提出了高速放电铣削粗加工与多轴联动电火花成形精密加工复合的加工工艺,通过对复杂流道构件的高速放电铣削加工电极损耗补偿和多轴联动电火花成形加工轨迹规划等技术的研究,实现了复杂流道构件的高效、高精度放电加工。     

加工高硬钢模具型腔用CBN立铣刀

随着IT相关产业的发展和技术进步,相关零件及其加工模具日益小型化。小型精密模具大多采用放电加工,加工时间长、效率低,还必须解决电极及其制造工艺的技术问题。为了缩短交货期、降低生产成本,加工方法正逐渐转向采用小直径球头立铣刀对模腔进行高速铣削。此外,减小切削深度、提高切削速度以及最大限度地提高进给速度的高效加工方法（高速铣削）也日益普及。     

电火花微细加工的工艺研究

本文以工艺试验为基础，结合电火花放电机理、固体材料的传热理论，研究了微能脉冲放电波形与加工表面形貌的关系及脉冲能量在工件与电极上的分配。     

电火花铣削加工工艺与算法研究

介绍了电火花铣削加工工艺及其有关计算方法。在大量实验的基础上,研究了微细电火花分层铣削加工,采用电极底面放电方式、电极轨迹规划、电极的损耗及补偿策略和合理选择分层厚度及电极微进给量等关键技术,提高了加工精度和效率。     

电解放电复合加工工艺研究及其在精密模具制造中的应用

分析了电解放电复合加工的机理和工艺特点,并介绍了电解放电复合加工在模具制造中的应用。     

粉末冶金模具加工方法及仿真技术的研究

粉末冶金模具的加工制造方法直接影响着粉末冶金制品的质量、开发周期及制造成本.线切割加工具有不需要特定形状的电极,加工几乎所有硬度、任何形状的工件,轮廓加工所需的加工余量小,利于少无切削,电极丝往复使用,损耗较小,加工精度高等特点,这种加工工艺非常适合于小批量多品种粉末冶金模具的加工.本文根据数控线切割加工粉末冶金模具的加工工艺方法,利用Pro/Engineer系统的Pro/NC模块,研究了粉末冶金模具型腔的数控线切割加工仿真,并自动生成了数控加工程序,从而将产品的计算机辅助设计(CAD)与计算机辅助制造(CAM)实现了无缝结合,大大提高了粉末冶金制品的制造精度,实现了加工自动化,缩短了开发周期,降低了制造成本.     

电加工电极专用石墨的物理特性及选用原则

阐述了电加工电极专用石墨的物理特性及其对放电加工工艺效果的影响,详细介绍了电加工电极专用石墨的选用原则,有助于根据加工需要科学地选用电加工电极专用石墨材料,提高电火花成形加工效果。     

转轮电极的线切割加工

介绍了在普通线切割机床上加工转轮电极的操作步骤,提高了转轮电极的制造效率和制造精度,拓宽了普通线切割机床的加工工艺范围,为普通线切割机床实施螺旋加工提供了一种行之有效的方法。     

电火花摇动加工微细阵列轴和孔的试验研究

针对微细阵列轴和孔的电火花加工,提出了利用数控电火花加工机床摇动功能的摇动加工微细阵列轴和孔的方法.此法是基于电火花反拷贝加工的原理,先用丝电极在薄平板(中间电极)上按要加工的阵列轴和孔间距或数倍间距加工阵列小孔(直径0.1 mm以上),然后用加工的薄平板(中间电极)作电极,电火花摇动加工微细阵列轴(电极),最后用此微细阵列电极加工阵列孔.进行了电火花摇动加工微细阵列电极试验,得到了单电极直径为50 μm、长径比为16的3×3阵列电极,并用此电极在70 μm厚的不锈钢板上加工出单孔直径为70 μm的3×3微细阵列孔.试验结果表明,电火花摇动加工方法可实现微细阵列轴和孔的加工.     

Probability of precision micro-machining of insulating Si3N4 ceramics by EDM

Electrical discharge machining (EDM) is used as a precision machining method for the electrically conductive hard materials with a soft electrode material. But recently we succeeded to machine on insulating material by EDM. The technology is named as an assisting electrode method. The EDMed surface is covered with the electrical conductive layer during discharge. The layer holds the electrical conductivity during discharge. For micro-EDM, the wear of tool electrode becomes lager ratio than the normal machining. So the micro-machining is extremely difficult to get the precision sample.

In this paper to obtain a fine and precise ceramics sample, some trials were carried out considering the EDM conditions, tool electrodes material and assisting electrode materials. Insulating Si₃N₄ ceramics were used for workpiece. The machining properties were estimated by the removal rate and tool wear ratio. To confirm the change of micro-machining process, the discharge waveforms were observed. The micro-machining of the Ø0.05 mm hole could be machined with the commercial sinking electrical discharge machine.     

EDM turning using a strip electrode

Turning by electrical discharge machining (EDM turning) is an effective method to machine hard-to-cut materials. Generally, a wire-EDM is utilized in EDM turning because it is not concerned with electrode wear. However, wire-EDM turning has a slow machining speed due to its small machining area, and the wire may break due to overheating electrodes. For these reasons, its machining speed must be limited. In this study, a strip-EDM was created in an effort to overcome the problems in the EDM-turning process. This machining method used a conductive strip as an electrode. The strip was fed continuously, like a wire-EDM; therefore electrode wear was not a concern. One advantage of the strip-EDM was that it increased the material removal rate because of its large machining area and non-breaking electrode. In the experiments, machining characteristics were investigated according to machining conditions, and practical machining was carried out via fabrication of complex shapes on a shaft workpiece.     

A study of EDM and ECM/ECM-lapping complex machining technology

EDM (electrodischarge machining) and ECM (electrochemical machining)/ECM-lapping complex machining is investigated in this paper. First, EDM shaping and ECM finishing technology are investigated. These processes are carried out in sequence on the same machine tool with the same electrode (copper) and the same machining liquid (water). Two types of EDM and ECM complex machining are investigated. One is with a formed electrode, and the other is with simple-shape electrode scanning. The complex machining with electrode scanning is applied to produce small and various-shaped components without making a formed electrode. The EDM surface of 1 μm Ra is improved to 0.2 μm Ra by applying ECM. Second, in order to get a smoother surface, a new EDM and ECM-lapping complex machining technology is developed. The surface roughness of a machined hole is improved to 0.07 μm Ra by applying 2 min of ECM lapping. The surface finishing of a hole shape is demonstrated with the complex machining technology.     

Power metallurgy tool electrodes for electrical discharge machining

Electrodes in electrical discharge machining (EDM) can be compared with cutting tools in conventional machining. Tool performance is one of the important factors that determine the quality of the machined component. Due to the ease of manufacturing and control over the properties of electrodes, the powder metallurgy (P/M) technique has an advantage over other methods of electrode fabrication. P/M electrodes affect the micro- and macrovariables in EDM and the properties of P/M electrodes can be controlled over a wide range by adjusting the compacting and sintering conditions. The performance of P/M electrodes on various aspects of EDM operation is discussed in this paper.     

基于旋转电极的方孔电火花加工新方法

提出一种方孔电火花加工新方法,利用具有勒洛三角形截面形状的工具电极在等宽方形约束孔中转动,使电极沿横截面扫过一个正方形区域,从而通过电极底面放电加工出方孔。分析了勒洛三角形电极在与其等宽的方孔中的运动方式和轨迹,设计了基于旋转电极的方孔电火花加工装置,通过实验验证了该方法的可行性。在不同的开路电压下,分别利用旋转的勒洛三角形电极和不旋转的方形电极进行方孔加工,发现旋转的勒洛三角形电极加工效率更高、电极损耗更低。     

小孔的等面积分流法电火花加工试验研究

介绍一种金属材料小孔的等面积分流法电火花加工.在电火花成形机上,通过改变制作电极的方法,采用电极等面积分流方法和稳定加工参数,进行机床稳定状态的临界面积以下尺寸的小孔加工.研究结果表明,等面积分流条件下,用相同加工参数,分流法的加工速度和放电间隙略有减小,而电极损耗稍稍变大.用分流法电火花加工小孔与不分流相比加工速度、放电间隙、电极损耗基本相似.研究结果证明,用分流法电火花加工小孔可改善机床的微小孔加工性能.     

转向直拉杆锻模型腔的电火花加工

以微型车转向直拉杆零件锻模型腔的电火花加工为例 ,对锻模型腔的电火花加工方法 ,电极的设计方案与制造工艺进行了分析和探讨 ,提出了一种可以保证模具型腔有足够重复精度的电火花加工电极的设计与制造方法     

模具型腔电极的设计及其应用

以孔形型腔和手机模具型腔为例,探讨两种情形下电极的设计以及根据电极的实际加工尺寸和机床的加工参数表选择电火花加工参数的过程,以便在实践中更好地掌握电火花加工技术。