电火花切割加工技巧探析

目前,在国防和民用领域的科研与生产中,电火花线切割加工得到了越来越广泛的应用。主要用于各类难加工材料、加工表面复杂,以及有特殊要求的模具、刀具和零件加工。本文从电火花线切割加工的特点出发,对电火花切割加工技巧的运用展开探讨。     

线切割加工工艺中加工参数对加工质量的影响分析及合理选择

影响线切割的加工质量的因素有脉宽、脉间、峰值电流和平均电流、进给速度、毛坯厚度、排屑条件等。这些因素相互之间也产生错综复杂的影响。能否合理地安排加工工艺在电火花线切割的加工中显得尤为重要。从线切割加工的基本原理入手,通过对DK7725型线切割机床的应用与研究,分析了影响加工精度的因素,总结出保证线切割机床加工质量的方法及提高产品成品率的措施。     

电火花线切割实训课改模式探讨

电火花线切割实训作为高职院校工程训练的重要内容,能开阔学生专业视野,提高学生实操技能。针对传统电火花线切割实训环节中存在的教学模式单一、设备少、课时少等问题,从实训平台、流程、内容等方面进行较深入的分析及探索。     

太阳能光伏硅片切割技术及切割钢丝生产探究

近些年,全球太阳能电池的产量越来越高,虽然遭遇全球金融危机的影响,但是其产量仍然稳步增长,可见,太阳能光伏发电行业有很好的发展前景,在我国新能源市场开发中有重要作用,所以要进一步研究太阳能光伏相关技术,本文就对光伏硅片切割技术尤其是多线切割技术和切割钢丝质量问题进行探讨。     

硬质合金线切割技术研究

线切割技术在数控加工中占据着重要的作用,现阶段,硬质合金在数控加工的刀具中应用较为广泛,传统的机械切割难以满足硬质合金的要求,笔者从硬质合金线切割的现况出发,寻求以电火花线切割来加工进行相关问题的研究。     

多晶超薄太阳能级硅片制造技术研究

文章的主要研究方向就是利用传统多线切割原理,通过不断降低钢线直径及槽轮槽距,优化切割工艺,从而降低切割过程中的切割损耗及降低硅片厚度,提高硅料的利用率,提高每公斤出片率,使得原料成本得到降低。     

复合结构控制式光固化树脂金刚石切割刀片的开发

金刚石刀片被广泛地用作直线切割石材、陶瓷和玻璃等材料的工具。这种工具一般设有多槽,槽具有降低切割抗力和提高工具寿命的效果。在这种背景下,就单层刀片和多层刀片检验了光固化树脂在带槽刀片中的应用效果。提出了复合结构控制式刀片的方案,并通过试验调查了其切割性能。这种刀片对硅片的一系列切割试验证实,切割性能有了显著的改善。     

项目教学法在《数控电火花线切割机床》课程中的教学研究与实践

运用项目教学法对《数控电火花线切割机床》课程进行教学实践与研究。     

冲裁模线切割加工中特殊工艺的改善对策

通过线切割加工（Wire Cut Electrical Discharge Machining，WEDM）的工艺特性分析，提出了模具零件线切割的工艺要点及处理方法，并针对实际操作情况，提出了特殊工艺的改善对策，例如：尖角切割法、2次切割法及一次成型切割法等，以提高冲裁模线切割的加工精度和制造质量。     

小贴士

棉线是最好的新式切割工具 不用原来惯用的锯和刀来给车轮做胎纹，而我采用棉线切割苯乙烯或者树脂车轮上的花纹。这种使用棉线切割零件的方法很容易掌控，而且操作起来很精细，适合做开门、切割副翼、舵轮、板条和许多易脆零件等工作。     

干切混凝土时金刚石锯片振动及噪声的研究

干切混凝土时,金刚石锯片在实际工作过程中产生的振动和噪声是非常严重的。文章从理论上分析了混凝土锯切过程中的强振动、高噪音的原因。通过改变锯切速度、进给速度、切深以及通过采用两种不同的基体结构的锯片,研究了不同的切削参数以及锯片的结构对锯片振动和噪声的影响。在不同的锯切工艺参数和锯片结构下,测量了噪声值、噪声功率、噪声电压、振动功率和振动幅值,并对其进行频谱分析。可以从锯片的基体结构、金刚石节块的结构、锯切工艺以及锯机的整体性能等方面来进行改进,从而达到降低噪声与振动的目的。本文在理论分析和实验的基础上提出了一些降低噪声和振动的方法。     

Ultrasonic cutting of foods with inclined moving blades

Cutting with devices excited by ultrasound is a promising alternative to conventional cutting when the materials contain particles which differ in stiffness and elasticity from the surrounding bulk or when they consist of layers which exhibit largely differing mechanical properties. Aim of the present study was to evaluate the impact of ultrasonic excitation and blade inclination (slice-to-push ratio) on cutting forces and cutting work of different foods with a fast-moving device which was excited in a way that the direction of vibration was parallel to the edge of the blade. The results show that ultrasonic excitation significantly reduces cutting force, that the magnitude of cutting force reduction largely depends on the product, and that cutting force and cutting work increase with increasing cutting velocity. Whereas these interactions are because of the micro-saw movement of the cutting tool, it was not possible to explain the product-dependent response to blade inclination.     

Impact of Excitation and Material Parameters on the Efficiency of Ultrasonic Cutting of Bakery Products

ABSTRACT: Cutting with tools excited by ultrasound is increasingly applied in the food industry, especially for cheese, confectionary, and bakery products. Due to the lack of a thorough understanding of the separation process, most of the ultrasonic cutting systems are designed and applied on the basis of empirical knowledge. The aim of the study was to elaborate the impact of ultrasonic parameters, that is, amplitude and frequency, on the cutting process, and special emphasis was placed on resulting effects in the close vicinity of the cutting edge, which are reflected by the separation forces. To allow a direct investigation of the mechanical separation without artifacts due to secondary effects such as melting and cavitation, the crumb of different bakery products (for example, dark and white bread, yeast dumplings, and cake) were analyzed. The results show that the influence of ultrasonic amplitude and frequency can be expressed by the maximum vibration speed on the cutting edge. For each product, an increasing maximum vibration speed results in a particular reduction of the cutting force and an increased quality of the cut. The magnitude of the cutting force reduction is inversely related to a material-specific parameter c_x, which was calculated from the mechanical properties according to the speed-of-sound concept. Therefore, the determination of c_x allows a specific adjustment of ultrasonic amplitude and frequency to achieve optimum cutting quality.     

Ultrasonic cutting of foods: Effects of excitation magnitude and cutting velocity on the reduction of cutting work

The effects of vertical cutting velocity and the magnitude of ultrasonic excitation on the reduction of the work necessary to separate various food materials were investigated. Generally, cutting work increased with increasing cutting velocity but, at each particular cutting velocity, decreased with increasing magnitude of the ultrasonic excitation of the cutting tool. Interactions between cutting velocity and the maximum vibration speed at the cutting edge, which is determined by both excitation amplitude and excitation frequency, are significant. Depending on the food under action, the relative amount of cutting work reduction is either affected by the maximum vibration speed or, additionally, by vertical cutting velocity. No distinct effects of the excitation frequency (20 or 40 kHz) were observed.

Industrial relevance

Ultrasonic cutting is used in the food industry, especially for the separation of products consisting of layers with different rheological properties to achieve minimally damaged cut surfaces. The results of the study may be useful for selecting operational variables (cutting velocity, excitation amplitude) during cutting to achieve a controlled reduction of the cutting work.     

固结磨料加工硅片的技术进展

随着集成电路(IC)制造技术的飞速发展，为了进一步增加IC芯片的产量和降低单元制造成本，硅片趋向大直径化。高质量、大尺寸硅片的制造对超精密加工技术提出了更加严峻的挑战。简要地介绍了传统的及目前流行的硅片加工工艺，讨论了在线电解修整(ELID)辅助磨抛硅片技术；最后，针对团结磨具中存在的超细磨料团聚问题，介绍了几种新型的磨抛盘制备技术。     

金刚石超精密切削技术探讨

金刚石超精密切削技术是超精密加工技术的重要组成部分,直接影响尖端技术和国防工业的发展。金刚石超精密切削技术涉及的方面有很多,文章对刀具的选用、刀具制造技术以及超精密加工切削用量、加工机床等是金刚石超精密切削的关键技术进行了研究与探讨。图2表1参10     

树脂结合剂金刚石线锯的研究进展

随着太阳能电池制造业的发展,大直径硅片需求量日益增加,线锯切割技术得到广泛应用.文章概述了树脂结合剂金刚石线锯的研究现状,并提出树脂结合剂金刚石线锯的发展趋势是研究多层树脂结合剂金刚石线锯、缩小锯丝直径、采用高分子材料代替金刚石磨粒、提高锯丝使用寿命.     

纸样剪切设计在服装造型中的运用

摘要：纸样剪切设计是服装结构设计常用的方法,在塑造服装造型中发挥着重要的作用。随着服装设计的不断发展,服装造型越来越变化多样,为适应这些变化,纸样设计的方法也越来越多。本文在分析常见和新颖时尚服装造型纸样剪切的基础上,对剪切方法及其后续展开方式进行归类,把剪切方法分为边缘剪切、内部剪切和全部剪切,后续展开方式分为平行展开和旋转展开,并分别阐述剪切和展开的原理,还运用实例分析了各自的实现方法,尤其对新颖时尚款式的剪切设计进行坯布试验,为纷繁芜杂的服装造型寻找相应的剪切方法提供参考。     

花样激光自动裁剪系统的DSP控制

为了实现服装面料优质高效裁剪,引入激光裁剪技术,采用具有丰富外设资源的DSP处理器TMS320F2812,运用正切运动插补算法,研究开发了激光自动裁剪控制系统,克服了传统机械裁剪刀具切削引起的震动,不但提高了面料或花样裁剪的质量,而且也提高了裁剪效能。在激光裁剪的原理和自动裁剪系统的总体设计基础上,完成了结构设计和硬件设计,同时配合软件设计,应用SD卡存储及FAT32文件管理程序实现轨迹控制文件的传输,结果表明：激光自动裁剪具有高精度高效率的裁剪效果。     

硅片化学机械抛光表面材料去除非均匀性实验

化学机械抛光技术已成为超大规模集成电路制造中实现硅片全局平面化的实用技术和核心技术。CMP的最大问题之一是硅片材料去除的非均匀性,它是集成电路对硅片表面平坦化需求的一个重要指标。文章提出了硅片表面材料去除非均匀性计算公式,在CP-4实验用抛光机上进行了硅片化学机械抛光实验,并用美国ADE公司生产的WaferCheck-7200型非接触式电容厚度测量设备对单晶硅片的厚度进行高精度检测,经过计算,得出了不同抛光速度下硅片表面材料去除非均匀性的数据,为理解硅片CMP材料去除非均匀性形成机理,进一步揭示硅片CMP材料去除机理提供了理论依据。