微结构超声复合加工机理分析与试验

提出制作微结构的超声复合电加工方法.分析微细超声、超声复合电火花、超声复合电解微细加工过程机理.用微细放电组合技术制作多种截面形状微细工具电极;完善超声复合电加工试验系统,进行了多种材料、形状的微结构超声复合加工试验.结果表明:用超声加工是制作硬脆材料微结构的有效方法,用超声复合电火花制作的金属材料微结构有好的精度及稳定性;超声复合电解加工兼有效率高、精度好的技术优势.     

Study on the Combined Machining Technology of Ultrasonic Vibration Assisted EDM in Gas Medium

介绍一种新兴的加工技术——超声振动-气体介质电火花复合加工技术,并通过机制分析和加工实验比较超声振动-气体介质电火花复合加工与普通气体介质电火花加工各项数据的差异,得出超声振动-气体介质电火花复合加工技术优于普通气体介质电火花加工的结论.     

非导电材料的电化学电火花复合加工工艺研究

概述了电加工非导电超硬材料的一个新方向－电化学电火花复合加工的加工原理，研究了物理充气方法和工具电极作超声振动对电化学电火花复合加工效率的影响。     

硬质合金的超声电火花复合加工试验研究

硬质合金主要用作工具和结构材料,由于它在结合方面的硬度、强度和耐磨性等独一无二的优良性质,使得它在现代工业中发挥着重要的作用.但因其强度很高,所以不易被传统的机械加工技术加工.针对这些特点进行了超声电火花复合加工试验,研究了脉冲宽度、超声振幅、磨粒大小对加工效率以及表面粗糙度的影响.     

聚晶金刚石电火花超声机械复合加工技术研究

聚晶金刚石具有优良的力、热、化学、声、光、电等性能,在现代工业、国防等领域中得到日益广泛的应用。但是,聚晶金刚石硬度高,耐磨性好,其成型加工非常困难,超声电火花机械复合加工技术是一种有效的加工方法。本研究在分析电火花超声机械复合加工原理的基础上,采用青铜结合剂金刚石砂轮实现了聚晶金刚石的超声电火花机械复合加工。实验分析了超声电火花机械复合加工过程工艺参数与加工效果之间的关系,结果表明,脉宽、脉间、峰值电流、超声振幅、开路电压等参数对复合加工过程工艺结果的影响程度较明显。     

第18届国际电加工会议综述

对第18届国际电加工会议论文进行了综述,介绍了近年来国际特种加工领域的最新研究进展。主要内容包括电火花成形加工、电火花线切割加工、电化学加工、超声加工、激光加工、增材制造、微细特种加工及相关复合加工工艺的研究成果。     

超声电火花复合加工钛合金表面质量研究

采用电火花加工及超声电火花复合加工的方法对TC4钛合金进行了加工实验,分析了小电参数下两种加工方法中脉宽和峰值电流对表面粗糙度的影响,研究表明超声电火花复合加工可有效地降低零件表面粗糙度值.通过扫描电镜对零件表面形貌的分析和重熔层厚度的观测以及零件表面X射线衍射分析,表明采用超声电火花复合加工钛合金零件可获得较好的表面质量.     

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。     

超声振动复合微细电火花加工微小孔试验研究

微小孔加工时的放电间隙较小,排屑、消电离状态差,放电效率低,直接影响加工效率和电极损耗;超声振动可改善排屑、消电离状态,能提高放电效率。将超声引入微细电火花加工,通过工件的超声振动,进行超声功率、小孔孔径、脉冲频率的微小孔电火花加工工艺试验研究,结果表明:加工不同孔径时,超声功率及电源频率都存在一个最佳值;加工条件合适时,超声复合微细电火花加工优于常规微细电火花加工。     

倒置式电火花超声复合加工装置

为了解决大深径比微孔的难加工问题,提出了倒置式电火花超声复合加工的想法.并在原理性实验装置与加工实验的基础上,开发设计了基于工件附加超声振动方案下的改进型加工装置--倒置式电火花超声复合加工装置.主要完成了装置的总体方案设计、功能部件设计和性能分析,并针对装置的技术难点,提出了解决途径.     

Material removal mechanisms of cemented carbides machined by ultrasonic vibration assisted EDM in gas medium

A new electrical discharge machining (EDM) technology named tool electrode ultrasonic vibration assisted electrical discharge machining in gas medium (UEDM in gas) is proposed and its principle is introduced. Relevant experimental equipment was designed by which a series of machining experiments of cemented carbide material were carried out. The mechanisms of cemented carbide material removal are discussed in detail through observing and analyzing the microstructures of machined surface. Five material removal mechanisms of cemented carbides machined by UEDM in gas were proposed, which are melting and evaporation, oxidation and decomposition, spalling, the force of high-pressure gas and the affection of ultrasonic vibration.     

超声振动磨削放电复合加工SiCp／Al试验研究

针对SiCp／Al的加工,提出一种超声振动磨削放电复合加工的方法．从加工效率、加工稳定性及表面质量等方面与电火花加工进行了对比试验研究。分析了两种加工方法的脉冲宽度和峰值电流对加工速度和表面粗糙度的影响,结果表明：电火花加工的表面粗糙度平均值为尺04．5μm,超声振动磨削放电复合加工的表面粗糙度平均值为Ra2μm：超声振动磨削放电复合加工的稳定性比电火花加工好,但加工速度较低。通过扫描电镜对两种加工方法下零件表面形貌和重熔层进行了观测,对试件表面进行了X射线衍射分析,表明采用超声振动磨削放电复合加工SiCp／Al复合材料可获得较好的表面质量。     

工作液超声振动辅助电火花小孔加工装置设计与试验

电火花加工小孔存在电蚀产物排出效率低导致加工效率低、电蚀产物排除导致二次放电现象影响加工精度等问题,而超声振动在工作液中产生空化效应和泵吸作用,能大幅提高电火花的排屑和消电离能力,进而在很大程度上减少上述问题的发生。设计一套工作液超声振动辅助电火花小孔加工装置,主要包括主轴系统、微三维运动平台、超声振动工作液槽和数据采集系统,其中主轴系统包括NSK电主轴、引电结构、工具电极装夹结构,可以实现工具电极的高速旋转;基于LabVIEW开发了电火花小孔加工控制系统,主要包括初始化模块、粗定位模块、恒电压对刀模块、实时电压分段控制加工模块和实时显示模块。开展了工作液超声振动辅助电火花小孔加工试验研究,试验结果表明：随电火花加工电压的增加,工件材料去除率和电极损耗率都趋于增大。     

Performance and Surface Integrity of Ti6Al4V After Sinking EDM with Special Graphite Electrodes

Titanium and its alloys have high chemical reactivity with most of the cutting tools. This makes it difficult to work with these alloys using conventional machining processes. Electrical discharge machining (EDM) emerges as an alternative technique to machining these materials. In this work, it is investigated the performance of three special grades of graphite as electrodes when ED-Machining Ti6Al4V samples under three different regimes. The main influences of electrical parameters are discussed for the samples material removal rate, volumetric relative wear and surface roughness. The samples surfaces were evaluated using SEM images, microhardness measurements, and x-ray diffraction. It was found that the best results for samples material removal rate, surface roughness, and volumetric relative wear were obtained for the graphite electrode with 10-μm particle size and negative polarity. For all samples machined by EDM and characterized by x-ray (XRD), it was identified the presence of titanium carbides. For the finish EDM regimes, the recast layer presents an increased amount of titanium carbides compared to semi-finish and rough regimes.     

Possibilities of laser-beam joining cemented carbides to steel

Welded joints of cemented carbides with steel are commonly present in tool production, mainly those used in the machining and mining industry. The article presents possibilities of joining cemented carbides H10S and G10 with steel C45 using laser radiation. These are the first innovative experiments carried out in Poland. Joints between cemented carbides and steel were made both directly and using spacers between the materials to be joined, which were made of copper, triple-layer solder Ag49/Cu and nickel. The joining trials were carried out at the Laser Technology Centre of the Institute of welding in Gliwice. A Triumpf disc laser (λ = 1030 nm) Tru-Disc 12002 with output power of 12 kW was used for this purpose. The laser beam was focused mostly on the steel surface to avoid direct interaction between the laser beam and the structure of cemented carbides. The assessment of joints of cemented carbides with steel C45 was conducted on the basis of metallographic evaluation, EDX analyses and microhardness measurements.     

A review on current research trends in electrical discharge machining (EDM)

Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporising. The electrode and the work piece must have electrical conductivity in order to generate the spark. There are various types of products which can be produced using EDM such as dies and moulds. Parts of aerospace, automotive industry and surgical components can be finished by EDM. This paper reviews the research trends in EDM on ultrasonic vibration, dry EDM machining, EDM with powder additives, EDM in water and modeling technique in predicting EDM performances.     

纵扭超声振动电火花加工微小孔仿真研究

超声振动电火花加工是一种高效加工微小孔的新型加工方法,能够提高加工效率与精度。对纵扭超声振动电火花加工微小孔进行研究,建立描述电极丝周围间隙工作液流动特性的数学模型,使用Fluent对数学模型进行验证,同时加入切屑,对间隙工作液运动情况以及排屑情况进行探究。结果表明：在电火花加工时,在电极丝引入纵扭超声振动,流体域有明显的扭转运动,电极丝底部切屑在离心力的作用下,更易从底隙中进入侧隙,随工作液的运动排出孔隙,有效防止底部产生切屑堆积,提高了电火花加工微小孔的精度。     

复杂型面的复合光整加工实验研究

利用电火花-超声和脉冲电化学复合加工工艺对三维复杂型面的光整加工进行了研究,论述了电火花超声复合加工的原理及超声装置的设计,进行了工艺参数实验研究,通过Master CAM软件实现型面的造型、编程,进行了三维型面的精密成形加工,经过脉冲电化学抛光后使型面达到镜面效果.