金刚石微粉砂轮电火花修锐微观研究

电火花修锐是金属结合剂粗粒度金刚石砂轮的理想修锐方法，研究表明，金属结合剂金刚石微粉砂轮的电火花修锐表面形貌同金属结合剂粗粒度金刚石砂轮的电火花修锐及磨削法修锐有很大差别。本文从微观角度分析了金属结合剂金刚石微粉砂轮的电火花修锐特性及其影响因素。     

在线电解修锐(ELID)磨削液的成膜特性实验研究

ELID技术是金属结合剂超硬磨料砂轮修锐的一种重要方法，ELID磨削液的选择是否合理将直接影响修锐的质量和效率。磨削液成份种类的选择以及它们之间的配比关系对砂轮表面氧化膜的生成速度、硬度、致密性、粘附性、以及绝缘性等方面都有很大的影响。本文针对青铜结合剂金刚石砂轮，对几组不同配比关系的磨削液进行了电解及成膜能力实验，通过观察电解过程电流的变化规律以及电解后阳极表面生成氧化膜的质量，较准确地对磨削液的成膜特性进行了评定，确定了磨削液配比优化方案，为青铜结合剂金刚石砂轮ELID磨削的实现奠定了理论与实验基础。     

超硬磨料砂轮的激光修锐技术研究

激光修整超硬磨料砂轮的原理,利用Ｎｄ：ＹＡＧ固体脉冲激光器进行激光修锐青铜结合剂和树脂结合剂硬磨料砂轮的试验,用扫描电镜观察了激光修锐前后砂轮表面的微观表貌,对激光作用下砂轮表面不同结合剂材料的去除机理进行了分析,通过磨削陶瓷试验,研究激光修锐的金刚石砂轮的磨削性能,并与普通砂轮磨削肖修锐的金刚石砂轮进行对比。结果表明,采用试验所确定的激光参数可选择性地去除砂轮表面的结合剂材料,而不损伤超硬磨粒,     

砂带修锐树脂结合剂CBN砂轮的研究

砂带修锐树脂结合剂ＣＢＮ砂轮的研究南京航空航天大学李迎，徐鸿钧，张幼帧一、砂带修锐原理超硬磨料磨具的修整分整形和修锐两个过程．而修锐是目前超硬磨具修整工作中的难点。电解在线修锐成功地解决了金属结合剂超硬磨料磨具修锐问题（１），使树脂结合剂ＣＢＮ砂轮的...     

辅助侧向吹气法金刚石砂轮激光修锐试验与评价

介绍了辅助侧向吹气法金属结合剂金刚石砂轮的激光修锐试验和简化测力评价方法,计算比较了修锐前后砂轮磨削力、磨削力比和比磨削能,从不同角度说明了辅助侧向吹气法对激光修锐金属结合剂金刚石砂轮的有效性。分析了修锐前后砂轮表面与对应磨削试件表面的微观形貌机理,解释了影响磨削力变化的因素。采用辅助侧向吹气法能够解决金属结合剂砂轮激光修锐中常见的熔化覆盖问题,使砂轮磨削力比同轴吹气法修锐下降5％～7％,激光修锐砂轮的磨削性能得到明显改善。     

陶瓷结合剂金刚石磨具制备工艺研究

研究了以25％左右的陶瓷结合剂和75％左右的金刚石磨料在720℃～750℃的温度下烧结,保温4～8h制备陶瓷结合剂金刚石磨具的工艺。磨具的气孔分布、显微结构、抗弯强度和磨削性能等基本达到国外同类产品的质量。实验表明磨具的气孔率、显微结构、抗弯强度和磨削性能受磨料配方、陶瓷结合剂的加入量、成形压力、烧结温度和保温时间等工艺因素的影响。     

一种多孔金属结合剂金刚石砂轮节块孔隙率的试验研究

与传统金属结合剂金刚石砂轮相比,多孔金属结合剂金刚石砂轮在难加工材料磨削加工时具有磨料易出刃、修整修锐方便和磨削效率高等优点。以人造金刚石、Fe∶Ni-Cr合金金属结合剂及造孔剂为原料,通过真空高温烧结法,制备多孔金属结合剂金刚石砂轮节块。通过排液法测定节块试样的孔隙率,研究原料及其不同配比对节块孔隙率的影响规律,为多孔金属结合剂金刚石砂轮制作提供试验数据。     

电镀金刚石磨具电解法修锐工艺研究

本文介绍了电解法修锐电镀金刚石磨具的装置和工艺,分析了该法用于修复玻璃磨削用电镀金刚石砂轮的效果,讨论了影响修锐效果的工艺因素。研究结果表明,电解法修锐电镀金刚石磨具是适宜的,可大幅度提高磨削效率,使电镀金刚石磨具得到充分利用,有显著的经济效益。     

HIPSN轴承套圈内表面磨削力的测试与分析

采用树脂结合剂金刚石砂轮对热等静压氮化硅(HIPSN)陶瓷轴承套圈的内表面磨削,通过磨削力的测定以及磨削力比和比磨削能的计算,分析陶瓷材料的去除机理.该试验中陶瓷材料的去除机理以脆性去除为主并伴随有塑性去除;减小径向进给速度、提高工件转速可以增加切向磨削力,增加塑性去除,改善磨削表面质量.     

金刚石砂轮金属结合剂的气中单脉冲电火花放电去除机理

针对金属结合剂金刚石砂轮修锐困难的问题,提出采用气中电火花接触放电修锐的方法。为有效地实现微细金刚石砂轮的修锐,建立单脉冲电火花放电去除加工的试验系统,研究金属结合剂的气中和液中电火花放电去除机理。在试验研究中,主要分析无负荷电压和放电极性对脉冲放电电流、脉冲放电间隙、脉冲放电去除量、电极磨耗比等的影响。结果表明,正极性不易发生短路现象,而且气中的脉冲放电间隙小于液中的 ,适应于微细金刚石砂轮的修锐。此外,在气中放电中存在由绝缘破坏引起的火花放电向附有电弧柱的电弧放电转变的临界无负荷电压,且电火花放电的去除量可以明显小于电弧放电的去除量,但是当无负荷电压小于某一定值时电极消耗比会快速增加。修锐的试验结果显示,利用气中单脉冲电火花放电去除加工条件可以实现金属结合剂微细金刚石砂轮的修锐,产生较好的砂轮出刃形貌,改善磨削表面质量。     

The mechanism and application of bronze-bond diamond grinding wheel pulsed laser dressing based on phase explosion

This paper presents a theoretical analysis of the surface bond removal mechanism for bronze-bond diamond grinding wheels using a pulsed laser. For the first time, the existence of a phase explosion phenomenon during the process of grinding wheel laser dressing is proposed, and the negative effects of a phase explosion on laser dressing are analyzed. Additionally, a theoretical study on phase explosion is conducted. The mechanism of bronze-bond diamond grinding wheel laser dressing is improved, and theoretical guidance for bronze-bond diamond grinding wheel laser dressing is provided. In the experiment, the processing parameters of the laser during phase explosion are studied, and a grinding test under the corresponding conditions is conducted. A high-speed camera is used to observe phase explosion in the laser dressing process. An ultra-depth 3-D microscope system is used to observe the topography of the bronze-bond diamond grinding wheel after dressing and grinding as well as the bronze wheel surface quality. It is concluded that to avoid phase explosion from occurring in the laser dressing of the bronze-bond grinding wheel, chip space around the bond must exist for the abrasive particle protrusions. The processing parameters of laser dressing under certain condition are optimized, and the desired dressing effect is achieved.     

A study on the development of in-process dressing lapping wheel and its evaluation of machining characteristics

Ceramics, carbide, and ferrite are widely used due to their significant mechanical properties such as light weight, chemical stability, super wear resistance, and electronics. Despite these characteristics, this material is not widely used for its difficulty in machining material. Therefore, the method of using a metal bonded wheel was proposed. However, a metal bonded wheel is difficult to dress. Recently, a new technology is being developed for In-Process Electrolytic Dressing to solve this problem. This technology provides dressing for metal-bonded wheels during the lapping process for in-process lapping of protruding abrasive from super-abrasive wheels. This method requires a wheel for electrolytic dressing, a power supply, and an electrolyte. A cast iron bonded diamond (CIB-D) wheel is dressed by electrolytic dressing and its electrolytic characteristics are evaluated. This study produced an ultra-precision lapping machine for in-process electrolytic dressing using super-abrasive CIB-D applied for lapping ceramics, sintered carbide, and optical glass.     

A study on wear mechanism and wear reduction strategies in grinding wheels used for ELID grinding

Metal-bonded superabrasive diamond grinding wheels have superior qualities such as high bond strength, high stability and high grindability. The major problems encountered are wheel loading and glazing, which impedes the effectiveness of the grinding wheel. Electrolytic in-process dressing (ELID) is an effective method to dress the grinding wheel during grinding. The wear mechanism of metal-bonded grinding wheels dressed using ELID is different form the conventional grinding methods because the bond strength of the wheel-working surface is reduced by electrolysis. The reduction of bond strength reduces the grit-depth-of-cut and hence the surface finish is improved. The oxide layer formed on the surface of the grinding wheel experiences macrofracture at the end of wheel life while machining hard and brittle workpieces. When the wheel wear is dominated by macrofracture, the wheel-working surface is free from loaded chips and worn diamond grits. When the oxide layer is removed from the wheel surface, the electrical conductivity of the grinding wheel increases, and that stimulates electrolytic dressing. The conditions applied to the pulse current influence the amount of layer oxidizing from the grinding wheel surface. Longer pulse ‘on’ time increases the wheel wear. Shorter pulse ‘on’ time can be selected for a courser grit size wheel since that type of wheel needs high grinding efficiency. Equal pulse ‘on’ and ‘off’ time is desired for finer grit size wheels to obtain stable and ultraprecision surface finish.     

Wear mechanism of metal bond diamond wheels trued by wire electrical discharge machining

The stereographic scanning electron microscopy (SEM) imaging was used to investigate the wear mechanism in wire electrical discharge machining (EDM) truing of metal bond diamond wheels for ceramic grinding. A piece of the grinding wheel was removed after truing and grinding to enable the examination of wheel surface and measurement of diamond protrusion heights using a SEM and stereographic imaging software. The stereographic SEM imaging method was calibrated by comparing with the profilometer measurement results. On the wheel surface after wire EDM truing and before grinding, some diamond grain protruding heights were measured in the 32 μm level. Comparing to the 54 μm average size of the diamond grain, this indicated that over half of the diamond was exposed. During the wire EDM process, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruded in the gap between the wire electrode and wheel. These protruding diamond grains with weak bond to the wheel were fractured under a light grinding condition. After heavy grinding, the diamond protrusion heights were estimated in the 5–15 μm range above the wear flat. A cavity created by grinding debris erosion wear of the wheel bond could be identified around the diamond grain.     

异形滚柱的在线电解修型成型磨削工艺试验研究

介绍了一种用于汽车和摩托车上先进超越离合器异形滚柱的在线电解成型(ELID)磨削加工工艺试验及相关设备与装置,主要包括成型磨削的工艺实施方案,在平面磨床上实现成型磨削的工装设计及在线电解砂轮修型的装置设计与布局等问题。理论上分析了ELID成型磨削在加工中能按照理想的成型曲线自动修正砂轮母线的形状,从而达到很高的形状精度和较低的表面粗糙度。总结了影响加工质量和效率的因素和规律;同原来的成型拉削相比,采用成型磨削具有效率、质量与稳定性、工具成本和管理等方面的诸多优势。     

Ultra-precision lapping of machinable ceramic Si3N4-BN by in-process electrolytic dressing

The machinable ceramic Si₃N₄-BN is a material which is increasingly being employed for automobile bearings and machinable ceramics. This material is very hard and has high resistance against volatile temperature and wear. It's efficient quality and accurate surfaces have always been of high demand for many applications in the industrial field. Besides, this material is varied by the percentage of BN contained in it, and the characteristics of lapping also varies according to this percentage of BN. Hence, in-process electrolytic dressing for ultra-precision lapping was introduced and used to experiment with the differing BN percentages in machinable ceramic Si₃ N₄. Metal-bonded super-abrasive diamond lapping wheels have superior qualities such as high bond strength, high stability and high machinability. The major problems encountered are wheel loading and glazing, which impedes the effectiveness of the cast-iron bonded diamond lapping wheel and, therefore, dressing should be considered. In this respect, in-process electrolytic dressing (IED) is proposed as an effective method regarding continuous protruding abrasives on the surface of wheels, whereby loading and glazing phenomena can apparently disappear. In this paper, the machining characteristics of machinable ceramic Si₃N₄-BN have been studied by adapting the IED lapping process in terms of the percentage of h-BN material.     

微晶玻璃超精密磨削技术研究

分析实现微晶玻璃超精密磨削的技术条件和在线电解修整超精密磨削机理,并采用铸铁基金刚石砂轮结合在线电解的磨削方法对微晶玻璃进行了精密磨削,获得Ｒａ为２．３０８ｎｍ的超光滑表面。     

A Study of the Mirror-Like Grinding of Sintered Carbide with Optimum In-Process Electrolytic Dressing

Sintered carbide is widely used as the material for tools and die moulds, but it is difficult to grind because of its brittleness and hardness. A superabrasive diamond wheel is required for mirror-like grinding of this material. The completion of in-process dressing of a superabrasive wheel makes possible effective precision grinding of sintered carbide. This study proposes a new in-process electrolytic dressing system for this purpose. Using optimum in-process electrolytic dressing, the surface roughness is improved and the grinding force is very low. Optimum in-process electrolytic dressing has proved to be a good method for obtaining efficiency and mirror-like grinding of sintered carbide.