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.     

精密铝零件的电化学去毛刺

介绍了一种计算机硬盘铝零件的电化学去毛刺工艺。解决了零件变色这一关键问题。     

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.     

带钢表面氧化层湿式抛丸清理技术

目前绝大部分钢铁公司带钢表面氧化层的清理主要通过酸洗工艺或干式抛丸设备,然而这些表面处理工艺存在污染环境,过酸洗,灰尘、弹丸分离效果差,带钢表面划痕明显等问题。文中分析、整合了抛丸和喷丸技术的环境污染小,带钢表面无划痕,抛丸参数可控、易调节,不会过清理等优点,在常规抛丸设备中引入水系统,提出了一种湿式抛丸处理工艺,开发了一台湿式抛丸设备。通过PLC及触摸屏人机控制,完成了抛丸设备抛丸器,带钢移动小车,斗式提升机等不同部件的协调运动。利用有限元软件ANSYS/LSDYNA进行动力学仿真,分析并优化了抛丸参数对带钢表面性能的影响关系。试验表明,湿式抛丸可以有效清除带钢表面氧化层,并且与酸洗和干式抛丸相比,有一定的优越性。     

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。     

基于PLC控制的湿式喷砂机研究与设计

针对传统干式喷砂粉尘污染严重、喷砂效果不均匀、生产效率低下等问题,设计一种基于PLC集中控制的湿式喷砂机。新型湿式喷砂机以压缩空气为驱动力,通过高速磨液射流的冲蚀磨削作用,实现强化工件表面、改善应力等工艺要求。通过CFD仿真优化了湿式喷砂机主要参数,通过方案改进解决了喷砂加工不均匀性问题,通过PLC控制器实现了喷砂加工自动控制问题。实际测试表明:经湿式喷砂后,粗糙度达到原有生产工艺要求,表面残余应力分布均匀一致,显著优于传统干式喷砂效果。湿式喷砂有效消除了传统干式喷砂存在的粉尘污染等问题,操作简单方便,运行稳定可靠,兼具操作便利和应用经济性等优势,可广泛应用于金属工件的表面强化与改性处理等方面,具有较高的应用推广价值。     

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.     

航空航天铝合金构件装配孔钻削出口毛刺研究进展

航空航天制造业中存在大量的铝合金装配孔加工需求。装配孔主要通过钻削加工实现,加工中存在铝合金出口毛刺过大的问题。出口毛刺直接影响工件的精度、抗疲劳强度、装配性能,去毛刺工序会极大地增加工时和成本。因此有必要对铝合金装配孔钻削出口毛刺进行研究,实现对出口毛刺的控制。从铝合金钻削出口毛刺的类型和测量方法、形成机理和高度预测以及毛刺控制方法等方面进行了系统性的论述,以期为铝合金钻削加工出口毛刺的研究提供帮助。      

精密零件的微磨料气射流光整加工

近年来,在非传统去毛刺加工方法中,微磨料气射流去毛刺由于初始成本低、生产效率高、灵活性强、无应力、无热影响区,在精密零件的光整加工中获得了广泛的应用。本文详细介绍了微磨料气射流用于光整加工去毛刺的加工原理、材料去除机理、去毛刺的工艺参数以及对棱边尺寸的影响,并列举了一些微磨料气射流在不同应用领域的加工实例。     

摩托车铝合金气缸盖的金属型铸造工艺

采用金属型铸造工艺生产摩托车铝合金气缸盖,分析了金属型清理方法和预热温度、涂层厚度、下芯和合型操作、浇注温度及开型时间对铸件品质的影响,阐述了后处理,包括表面清理、磨光、热处理、抛丸处理和钝化处理等工艺控制在获得优质气缸盖产品中的重要作用。     

Deburring microparts using a magnetorheological fluid

It is difficult to deburr a micro-machined surface because the micro-features are easily damaged during the deburring processes. This paper proposes a new deburring process utilizing a magnetorheological fluid and applies it to the production of micromolds. A magnetorheological fluid is a functional fluid with a variable yield stress that is controlled by an external magnetic field. The proposed process utilizes two material removal mechanisms induced by the magnetorheological fluid flow. Extensive yielding of material is effective for deburring sheet-shaped burrs, and abrasive wear is effective for deburring protrusion-shaped burrs. A process model was developed to describe the effectiveness of each mechanism for specific burr geometries. The performance of the proposed method was verified experimentally. Metal burrs with a height of 200 μm and thickness of 1 μm were removed successfully with extensive yielding and abrasive wear. Burrs shorter than a few micrometers could be removed only by abrasive wear. The material removal behaviors of sheet-shaped and protrusion shaped burrs matched the proposed process model well.     

A method of etching and powder blasting for microholes on brittle materials

Brittle materials such as semiconductors, ceramics, glasses, piezoelectric etc., are difficult to machine by traditional machining methods. This paper provides an approach to create holes or grooves more efficiently via powder blasting process. Instead of one protective layer for mask that is conventionally used, two layers are coated on the surface of the substrate material. The inner layer is water-soluble resin with excellent adhesion to the substrate but having weak resistance to powder erosion, and the second layer is a photosensitive oligomer that is adhered well to the first layer and has very high resistance to powder erosion. Such a protective coating possesses two contrary characteristics: high resistance to powder blasting and easy removal from substrate after powder erosion. Once the openings of the second layer are formed at the desired positions via a photo-etching method, a printing method, or other methods, the holes or grooves can be obtained by etching through the openings of the second layer to the first layer and the substrate by a powder blasting process. Then the whole protective coating is easily and smoothly stripped off without any damage to the substrate by dissolving the first layer with water. Due to easy removal of the mask plus the good resistance to powder blasting and a much higher erosion rate than the one obtainable by wet and dry etching processes, the proposed process can be applied to create holes or grooves on brittle material, instead of chemical etching process, so as to achieve a good quality and superior rate of production.     

Corrosion of Al 7075 alloy during the production of aeronautic components: Influence of process parameters at the deburring stage

Aluminum alloys of the 7XXX series are widely used in aircraft applications. During the manufacturing of aeronautic components, the parts pass through four production phases (milling/drilling, deburring/adjustment, non‐destructive testing, and surface treatment) and come into contact with several kinds of fluids such as degreasing and cleaning solutions, which can lead to the occurence of surface defects due to localized corrosion, then requiring reworking or scrapping. The present study aimed at studying the influence of process parameters in the deburring/adjustment stage on the development of surface defects in 7075 alloy parts. The methodology consisted of design of experiments, immersion and drying tests, and surface analysis for quantification of corrosion damage. The results showed that the degreasing bath concentration and temperature, the immersion time of the aluminum parts in the degreasing solution, and the use of solvent pre‐cleaning had no significant influence on the quantity of surface defects. Therefore, these factors do not need to be rigorously controlled in the process. Clean washing water must be preferred and the parts must be dried in the stove at 110 °C in order to ensure a surface free of defects. The immersion and electrochemical tests showed that the occurrence of surface defects is lower in aged degreasing solution than in recently prepared solution.     

板坯连铸锤刀式去毛刺机的结构改进

在线锤刀式去毛刺机驱动系统结构复杂及去毛刺率低,本文对去毛刺机的传动系统结构进行了改进,省去原有的液压抱闸、减速机,由驱动电机和万向连轴器直接连接,使结构简化;并将锤刀与长销轴的连接孔由原来的圆孔改为长孔,使锤刀在长销轴的竖直方向的伸缩量增大,提高了去毛刺率,减少了毛刺对辊道的划伤,提高了铸坯质量.     

一种用于连铸大方坯的在线去毛刺机

在线去毛刺已成为连铸坯生产中的一个不可缺少的环节,它有效解决了因铸坯毛刺影响辊道寿命的问题,同时提高了轧钢的质量。研究设计了一种用于连铸大方坯的在线去毛刺机,在定尺长度的铸坯运输过程中对其分别进行前端和后端的去毛刺操作,去毛刺效果良好,且设备结构简单,体积小,易于维护。     

Experimental analysis of deburring process on inclined exit surface by new deburring tool

The removal of macro-burrs formed after drilling has always been a difficult engineering problem, especially on inclined exit surfaces with intersecting holes. A new deburring tool is developed to remove burrs on inclined exit surfaces. The performance of the proposed deburring tool is analyzed according to changes in parameters including tool geometry, the deburring direction, and cutting conditions. Based on our analysis, proper tool geometry is suggested, and an efficient deburring method and deburring conditions are determined which satisfy the chamfered geometry and surface roughness of holes.     

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.     

易燃易爆流体运储抑爆铝箔

介绍了易燃易爆流体抑爆材料的种类、抑爆效果、存在的问题、抑爆的原理。重点介绍了铝合金抑爆材料的各种性能及影响因素,铝合金抑爆材料的应用情况及市场前景。并详细介绍了带有抑爆铝合金网(球)的液化气瓶制作。建议建设专业抑爆铝箔厂。     

高压水喷射去毛刺技术的应用研究

以高压水去毛刺技术的基本理论为基础,针对液压阀结构特点,结合数控技术,提出高压水去毛刺方案,并对该方案的压力、流量、作用力与反作用力等关键参数进行计算.在此基础上,开发的HCC1000数控高压清洗中心具有去刺效率高、噪声低、清洗头不泄漏、价格低等特点.     

Tool life increase of coated carbide tools by micro blasting

In today’s production engineering nearly every cutting tool is coated. Since using the technology of coating different process chains for reconditioning have been developed. The last innovation is micro blasted coatings, which is the main topic of this paper. Concerning this topic influences on tool life have been investigated. Investigations on the tool life especially of hobbing tools were made thereby and coherences between coating bond, roughness and other attributes were discovered. The investigations were made with an aluminum oxide and a zirconium oxide as blasting abrasives and a variation of the blasting parameters pressure and period. The final result is an optimization of tool wear behavior by micro blasting of the coating.