磨料射流加工技术的发展与研究现状

与其他加工技术相比,磨料射流因具有无热损伤、高柔性、材料适用性强等特点,一直是国内外学者研究的热点。近年来,磨料射流被广泛用在微切割、微流道制备、表面抛光等领域,其发展趋势已经由宏观尺度向微观尺度转变,由粗加工向精加工转变。从射流的本质或根源来看,传统技术主要分为(磨料)水射流、浆体射流和磨料气射流。首先对上述各射流技术的发展背景、工作原理进行了综述。此外,还介绍了最近出现的多相射流和高压浆体射流等新技术。面对复杂的应用需求,如何挑选出合适的射流技术是一个难题。鉴于此,对各磨料射流技术的射流速度、工作压力、射流束直径、侵蚀轮廓和加工机理进行了深入分析和比较。最后对各磨料射流技术在微流道制备和表面光整加工等领域的应用情况以及存在的问题进行了论述,并详述了多相射流和浆体射流在表面抛光方面的优缺点。结果表明,磨料气射流拥有低压高速的优点,可以快速地去除材料。磨料气射流的缺点是射流易发散,需要结合掩模制备微流道。目前,掩模磨料气射流能加工宽度低至10 μm的微流道。浆体射流和磨料水射流的射流束直径已经可低至50 μm,能直接在表面刻蚀出大于50 μm的微流道。抛光应用中,浆体射流的材料去除率远低于磨料气射流,但表面粗糙度要好。考虑到两者的优点,多相射流试图在磨料气射流和浆体射流之间建立一个桥梁。同时,与浆体射流的W形侵蚀轮廓相比,多相射流的U形侵蚀轮廓更有利于表面抛光。     

微磨料空气射流加工技术的发展

微磨料空气射流加工(MAJM)技术是对硬脆材料进行微细加工的一种非常有潜力的技术，特别是对复杂的三维微细结构的加工。微磨料空气射流加工技术是基于传统的喷砂技术发展起来的，通过由空气喷射磨料微粒形成高速气流冲击工件表面而去除工件材料。与其它的加工技术相比，微磨料空气射流加工具有环境友好、易于控制、无热影响区、切口质量好等优点。本文介绍了此技术的基本加工原理、特点以及加工过程中的影响因素，论述了微磨料空气射流加工的材料冲蚀机理和切口特征。重点分析了一些主要的加工参数，例如空气压力、磨料材料、尺寸、供给率、喷嘴的形状和尺寸、喷射距离以及工件材料，对切削性能和切口特征的影响。并提出了微磨料空气射流加工技术中有待进一步深入开展的研究工作。     

LG8型倾斜式离心光饰机及光整加工

本文介绍了国内外光整加工的概况,着重介绍了倾斜式离心光饰机的结构、原理、光整加工工艺及其特点和应用。由于光饰机回转生产的离心作用及滚筒的合理倾斜,实现了滚筒内零件与磨料之间较复杂的相对运动,从而实现了光整加工。倾斜的滚筒有助于在离心力的作用下实现零件与磨料之间沿滚筒轴向的相对滑动,改善了水平式离心光饰机的缺点,从而提高了光整加工的效率及质量。本机采用了链传动,比皮带传动稳定可靠,使用寿命长。本文还扼要叙述了光整加工中对磨料与零件的配比、磨料及磨液的合理选择,这都是确保光整加工质量及效率的重要因素。     

磨料射流表面抛光研究综述

作为精密超精密光学制造工艺过程中的一个重要环节,各种新型表面抛光方法与工艺始终吸引着科研人员不断深入研究与探索。磨料射流抛光方法为小型复杂零件的表面抛光提供了一个新思路,成为精密超精密光学加工技术的重要组成部分。对磨料射流表面抛光过程中衍生的磨料水射流抛光、磁射流抛光、负压吸流抛光、磨料气射流抛光、冰粒水射流抛光、纳米胶体射流抛光的抛光原理、方法及特点进行了综述,分析了各射流表面抛光技术材料去除的最新发展;从加工原理、磨料选择、抛光精度、数学模型等方面对上述新型射流抛光技术进行深入分析与比较,其中磁射流抛光、纳米胶体射流抛光、磨料水射流抛光的抛光精度较高,可以实现表面粗糙度纳米级的超精密抛光,而磨料气射流抛光、冰粒射流抛光从加工成本上来讲则相对较低。最后,对磨料射流表面抛光在去除函数优化、精度效率的提高、应用范围扩展、在线检测、商业化应用等方面的发展趋势进行了预测。     

微磨料空气射流加工玻璃微流道结构研究

采用微磨料气射流加工技术(MAJM),对普通硅酸盐玻璃进行微流道槽加工.对通过掩膜加工与非掩膜加工效果相比较,得出在掩膜加工过程中,由于磨料的二次反弹冲蚀作用,所加工出的槽,槽壁较陡;在掩膜加工过程中,改变喷射距离、喷射压力、喷嘴移动速度和磨料流量四个加工参数,对加工槽的轮廓、加工过程中的材料去除率、磨料的流量效应进行研究,得出当喷射距离为4 mm,喷射压力为0.5 MPa,喷嘴移动速度为1.0 mm/s,磨料流量为0.117 g/s时,加工效果最好.通过倾斜喷射与掩膜加工相结合,研究了磨料磨粒的二次反弹冲蚀现象,为复杂三维微结构的加工,提供了一种新方法.     

微磨料水射流加工技术的发展

微磨料水射流加工技术的射流直径在10 μm～100 μm之间,较常规磨料水射流直径(500 μm～1200 μm)小一个数量级,在微加工领域仍保持常规磨料水射流的许多的性能,尤其适宜对硬脆材料、复合材料等难加工材料进行微加工.目前其孔加工精度已达到相当于激光微加工技术的水平.为加深对该新技术的最新发展的理解,本文介绍了微磨料水射流加工技术射流生成方式、装置设计的关键技术、主要参数对加工性能的影响及部分应用示例.最后提出了微磨料水射流加工技术中有待深入研究的工作.     

模具型腔自动化磁力研磨光整加工

介绍了自由磨粒磁力研磨光整加工机理,在3_TPT五自由度并联机床上对模具型腔进行磁力研磨光整加工试验,研究了磁感应强度、研磨间隙、磨料粒度以及研具表面形状对模具型腔进行磁力研磨光整加工的影响及其变化规律。     

光整加工

一、国内外零件光整加工技术概况金属零件的光整加工是指零件去毛刺;棱边倒角;倒园;表面抛光加工技术.电器制造、机械制造、仪器仪表制造行业在制造各种各样的金属零件的加工过程中,无论采用何种材料和工艺方法,无论加工技术和工艺设备如何先进,都会在相邻表面的交接棱边产生毛刺(或飞边),以及产生不允许存在的锐边;同时金属表面的锈蚀和粗糙面,往往是零件制造、功能和美观等诸方面要求所不允许的.为此,金属零件的光整加工是改善零件质量的必不可少的手段.     

基于3D打印航空发动机喷油管磁力研磨试验研究

目的针对镍基合金GH4169航空发动机喷油管进行磁力研磨光整加工试验研究,分析内置辅助磁极磁力研磨对工件内表面及交叉孔相贯线去毛刺的效果。方法利用磁粒研磨内置辅助磁极光整加工对工件内表面及内交叉孔相贯线处进行磁力研磨加工,通过研磨粒子与工件之间的划擦、磨削等运动,提高工件表面质量和去除内交叉孔相贯线处的毛刺。结果磁轭转速为1000 r/min,加工间隙为6 mm,采用圆柱形辅助磁极及平均粒径为250μm的磁性磨料时,其加工效果比传统的加工效果好,且效率更高,工件表面粗糙度从原始的5.8μm降至0.47μm(Ra0.5μm),内交叉孔相贯线处的毛刺明显被去除,且由于磁性研磨粒子的研磨作用,可对其进行二次光整加工。结论通过磁力研磨内置辅助磁极光整加工方法,原始工件内表面存在的褶皱、微裂纹明显得到改善,交叉孔相贯线处的毛刺也明显被去除。试验选用磁性研磨粒子粒径为250μm时,研磨效果最佳。通过磁力研磨光整加工后,管件能够得到良好的表面效果,提高了管件的综合性能。     

液压阀零件光整去毛刺工艺技术

本文内容是广州机床研究所在液压阀生产中,有关零件的光整及去毛刺工艺技术问题。全文分三部分:Ⅰ、简述液压传动应用和元件的主要技术要求,说明其去毛刺的重要性。Ⅱ、归纳本所液压零件去毛刺的几种方法:第一种方法是采用金刚石弹性刷和圆柱形磨料刷对主阀孔的光整及去毛刺工艺技术;第二种方法是采用圆盘刷、碗形刷的含料或不锈钢丝刷对液压阀结合面的去毛刺工艺技术;第三种方法是采用金刚石去毛刺工具对阀类零件的交叉孔去毛刺工艺技术;第四种方法是采用磨料尼龙圆盘形刷子或不锈钢丝轮对阀芯去毛刺工艺技术。这些光整及去毛刺的方法已在本所应用,效果很好。Ⅲ、关于去毛刺的检验情况。液压传动以其易于获得大的力或力矩,易于控制,易于实现直线往复运动或摆动,能进行较大范围的无级变速、传递均匀、平稳、容量大和结构简单等优点,已经在我国国民经济各     

Deburring microfeatures using micro-EDM

Demands for miniature components are rapidly increased in the field of optics, electronics, and medicine. Various machining methods have been introduced for the fabrication of complex three-dimensional microfeatures. However, burrs, which are an undesired but unavoidable by-product of most machining processes, cause many problems in assembly, inspection, process automation, and precision component operation. Moreover, as feature sizes decrease, burr problems become more difficult to resolve. To address this problem, several deburring methods for microfeatures have been introduced, including ultrasonic, magnetic abrasive, and electrochemical machining methods. However, these methods all have some shortcomings, such as mechanical damage, over-machining, changes in the material properties of the finished surface, sharp edge blunting, and the requirement for subsequent processing to remove chemical residues. In this study, microelectrical discharge machining (micro-EDM) using low discharge energy and a small-diameter cylindrical tool is introduced for deburring microfeatures. This method allows the machining of very small amounts of conductive materials regardless of the material hardness, and provides easy access to small microscale features for selective deburring. The burr geometry generated by the micromilling process was investigated to establish a deburring strategy using micro-EDM. The proposed method was verified by experimental results using aluminum, copper, and stainless steel workpieces.     

Wet blasting as a deburring process for aluminum

Light weight aluminum has shown high applicability in the automobile industry for high fuel efficiency. However, the manufacturing of aluminum is limited by the deburring process owing to the difficulty in employing wet blasting. In this paper, we present experimental and computational studies on the deburring process of wet blasting for aluminum. The process conditions are analyzed to achieve high deburring performance that minimizes the surface damage. Parameters of wet blasting with a significant influence on the deburring process are investigated and a promising deburring technique for aluminum is proposed.     

Electrochemical deburring system using electroplated CBN wheels

Deburring and edge finishing technology as the final process of machining operation is required for manufacturing of advanced precise components. Fitting a deburring process into FMS (flexible manufacturing system) with high efficiency and full automation is a difficult problem. There is no standardized procedure for the removal of burrs of various shapes, dimensions and properties and currently manual methods are used. In particular, deburring of internal cross holes which are perpendicular to a main hole is more difficult and the electrochemical method is a potential solution. Therefore, it is needed to develop the electrochemical deburring technology for internal deburring in a cross hole shape.In this study, the mechanism of electrochemical deburring by using electroplated cubic boron nitride (CBN) wheels is described and its deburring performance is investigated in an internal cross hole. Also, deburring efficiency for internal cross holes is examined with electrolytic currents and other electrochemical conditions. The optimum range of deburring the internal cross hole corresponding to the acquired edge quality is determined.     

Burrs—Analysis, control and removal

Increasing demands on function and performance call for burr-free workpiece edges after machining. Since deburring is a costly and non-value-added operation, the understanding and control of burr formation is a research topic with high relevance to industrial applications. Following a review of burr classifications along with the corresponding measurement technologies, burr formation mechanisms in machining are described. Deburring and burr control are two possible ways to deal with burrs. For both, an insight into current research results are presented. Finally, a number of case studies on burr formation, control and deburring along with their economic implications are presented.     

Improvement of workpiece quality in face milling of aluminum alloys

The compliance with the quality requirements of components is essential for the functionality of the whole product. With respect to parts with face-milled faces, the surface quality and the shape of the workpiece edges are of great interest. Frequently, these faces take over the function of seal faces where high demands on the surface integrity and burr formation exist. To ensure the workpiece quality that is required, nowadays additional processes for deburring are often necessary. To avoid deburring, the modification of machining processes is a promising approach. In this study, the influence of process cooling on workpiece quality is investigated. Using this approach, two effects are expected. The cooling is used to minimize a reduction of flow stress generated from the process heat, which than leads to a lower formability. The second effect relates to the kinetic energy of the snow blast for deburring by deformation and breakage of the burrs. Using a process cooling with carbon dioxide, the surface quality is enhanced and the burr formation is minimized.     

Robots in machining

Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task.     

Finishing effects of spiral polishing method on micro lapping surface

This study presents a spiral polishing method and a device for micro-finishing purposes. This novel finishing process has wider application than traditional processes. This offers both automation and flexibility in final machining operations for deburring, polishing, and removing recast layers, thereby producing compressive residual stresses even in difficult to reach areas. Applying of this method can obtain a fine polished surface by removing tiny fragments via a micro lapping generated by transmission of an abrasive medium through a screw rod. The effect of the removal of the tiny fragments can be achieved due to the function of micro lapping. The method is not dependent on the size of the work-piece's application area in order to carry out the ultra precise process. The application of this research can be extended to various products of precision ball-bearing lead screw. The proposed method produces products with greater precision and more efficiently than traditional processes, in terms of processing precisions and the surface quality of products. These parameters used in achieving maximum material removal rate (MRR) and the lowest surface roughness (SR) are abrasive particle size, abrasive concentration, gap, revolution speed and machining time.     

磨料流加工技术在热流道模具制造中的应用

为了解决模具热流道板的超细长流道孔及放射状细长热流道群孔的抛光和交叉孔去毛刺问题,首次将磨料流加工技术用于模具热流道的抛光。通过实例,介绍了加工工艺参数的选择或确定方法,指出了夹具设计要点,用图像比较的方法检测加工表面粗糙度值。实践证明,加工几分钟即可达到技术要求,其优越性在于抛光和去毛刺同时完成,抛光均匀性好、彻底去除了交叉孔的毛刺、加工效率高。该技术的高精度、高效、经济等特点为热流道模具的快速高精度制造提供了强有力的技术支持。     

纯钼与纯钛电化学去毛刺实验研究

为消除由纯钼和纯钛加工成的待加工件表面出现的金属重熔层和毛刺,选用电化学去毛刺工艺来去除这些待加工件上的金属重熔层和毛刺。电化学去毛刺工艺利用电化学阳极溶解的原理去除间隙的毛刺,其具有对工件无机械力、与工件材料硬度无关等优点因此其在加工高硬度和高韧性的金属工件上有着天然优势。通过使用不同电解液,运用电化学去毛刺的加工手段分别测试用电火花线切割加工过的钼片和钛片的去毛刺效果,得到了在30℃的电解液温度和5V的加工电压以及5s的加工时长下,电化学去毛刺加工在对纯钼和纯钛的加工上有着很明显的效果的结果。     

陶瓷基复合材料加工技术及其表面亚表面损伤机制研究进展

综述了陶瓷基复合材料的传统机械加工、超声辅助加工、激光加工、多能场复合加工等加工方式的研究进展,并简述了几种加工方式的优缺点.对陶瓷基复合材料的表面及亚表面损伤机制进行了总结和分析,包括材料表面亚表面损伤形式、材料表面亚表面理论及模型研究.提出了传统的陶瓷基复合材料加工技术需要进一步优化刀具材料、开发新的刀具结构、优化工艺参数等,以减少加工缺陷.研究了复合加工中材料去除率最大条件下的损伤容限条件、材料加工后的性能保持性等,同时探究了高效高质量的多能场复合加工新方法及其应用理论,以及研究探索了在复杂载荷及动载荷(如动态切削力、高温切削及超声动态冲击载荷)耦合作用下陶瓷基复合材料的内在损伤机理及演化问题.