电火花磨削

电火花磨削是在电火花加工工艺的基础上发展起来的,其蚀除金属的原理与一般电火花加工相同,机床运动形式与普通砂轮磨削相似,所以称电火花磨削。电火花磨削主要用来对硬质合金、钢结硬质合金和其它高硬度或难以磨削的金属(如铜和铝等)材料做的工模具进行精密成形磨削。同时,对于用普通砂轮磨削容易产生热变形的细而长、薄而脆的精密金属成形零件,采用电火花磨削更具有独特的优点。它还可以用来磨削平面、内孔与外圆。现以我们研制的DM20型电火花成型磨床为例,对电火花磨削工艺     

电火花机械复合磨削技术的研究进展

电火花机械复合磨削集合了机械磨削和电火花加工两种加工工艺,能够提高加工效率和加工质量,广泛应用于导电难加工材料的加工。本文对电火花机械复合磨削机理和研究现状进行了系统阐述,在分析现有研究成果的基础上,针对大口径Si C反射镜非球面成形磨削中存在的加工效率低、砂轮磨损严重等问题,提出了将电火花机械复合磨削应用于大口径Si C反射镜非球面成形磨削加工的观点,以提高其成形加工效率。     

基于电火花磨削的精密微型轴承内孔加工

针对2mm以下精密微型轴承内孔难以采用常规的磨削方法加工的现状，根据电火花小孔磨削的基本原理，在电火花小孔磨削装置的基础上，采用双辊棒支承工件的结构，加大加工时往复振荡的幅度和速度，合理转换电规准电参数，初步实现了精密微型轴承内孔的电火花磨削。     

电火花磨削加工状态的识别与伺服控制

针对优质超硬材料难加工的问题,分析了电火花磨削特性,研究了电火花磨削加工状态识别及检测方法,研制了间隙电压采样电路和专用模数转换卡及伺服控制系统,解决了电火花磨削加工过程中的关键问题,实现了加工过程的智能控制。实验证明,该系统运行稳定,安全可靠,加工效果明显。     

名词解释

<正>电解电火花机械磨削电解电火花机械磨削方法的技术关键是使用外圈上均匀分布着8~16个导电区的特制树脂结合剂砂轮,在特殊导电砂轮和被加工零件之间施加25~30V的直流电压,并注入具有导电性的低浓度电解液作为磨削液,使砂轮在进行机械磨削的同时,还通过电脉冲进行电解、电火花加工。对于非导电材料,在磨削区附近设置了电极,甚至以喷嘴作为电极,通过电解液形成电解和放电回路。在电解电火花机械磨削加工过程     

电火花修整金刚石微粉砂轮的磨削特性

地于金属结合剂金刚石微粉砂轮来说，电火花修整法是一种高效的修整方法，本文讨论了电火花后青铜结合剂金刚石微粉砂轮磨削工程陶瓷的磨削力、磨削工件表面粗糙度特性，并同常规磨削法修整进行了比较。     

超声振动辅助磨削脉冲放电复合加工工艺研究

利用超声振动、电火花脉冲放电的加工特点,将其同单一普通磨削优化组合,可以得到较好的加工效果。从加工表面粗糙度、表面微观形貌两个方面,比较了单一磨削、超声振动辅助磨削、磨削—电火花脉冲放电复合加工、超声振动辅助磨削—电火花脉冲放电复合加工的加工效果,得出了不同加工方法的优缺点。通过对几种加工方法的优化组合,设计了新的加工工艺。实验结果证明,新的加工工艺可以有效地提高加工表面质量,减少裂纹和热应力的产生。     

超声振动辅助磨削脉冲放电复合加工工艺研究

利用超声振动、电火花脉冲放电的加工特点,将其同单一普通磨削优化组合,可以得到较好的加工效果.从加工表面粗糙度、表面微观形貌两个方面,比较了单一磨削、超声振动辅助磨削、磨削-电火花脉冲放电复合加工、超声振动辅助磨削-电火花脉冲放电复合加工的加工效果,得出了不同加工方法的优缺点.通过对几种加工方法的优化组合,设计了新的加工工艺.实验结果证明,新的加工工艺可以有效地提高加工表面质量,减少裂纹和热应力的产生.     

电火花机械复合磨削加工钢结硬质合金的实验研究

提出采用电火花机械复合磨削加工钢结硬质合金，通过实验研究表明，复合磨削比电火花、纯机械磨削加工淬硬钢结硬质合金，可大幅度提高加工效率，降低砂轮损耗，提高表面质量。     

基于补偿块电火花磨削加工补偿电极试验研究

针对电火花磨削金属材料中出现的电极损耗现象,提出一种添加铝基补偿块的在线补偿电极的电火花磨削加工方法。金刚石磨头电极在1 440 r/min转速和1mm/min进给速度下,采用间歇喷雾的冷却方式磨削纯铝,得到铝碎屑粘附于磨头表面的现象。采用不同脉宽和峰值电流进行电火花磨削和加铝基补偿块电火花磨削304不锈钢的实验,对比电极相对损耗,可得出加补偿块后,电极相对损耗降低0.7倍,即该方法可在线补偿电极损耗。     

电火花修整超硬磨料砂轮技术发展现状

电火花加工技术的发展带动了电火花修整超硬磨料砂轮技术,改变了传统砂轮“硬接触”修整方法。近年来,许多学者致力于研究超硬磨料砂轮的电火花修整方法,为提高磨削效率和磨削精度做了大量有意义的研究。基于大量文献的论述与研究,回顾了近三十年来电火花修整超硬磨料砂轮技术发展过程的各种研究内容以及取得的成果,完整地阐述了电火花修整金属基超硬磨料砂轮技术的基本原理。以立方氮化硼(CBN)和金刚石磨料砂轮修整为主要应用,对不同电极、不同放电介质、不同放电参数以及现代工程理论辅助下的建模分析方法等方面做了介绍,分析了现有电火花修整技术发展中存在的问题,探讨了未来发展的方向及趋势。     

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.     

On the temperature and specific energy during electrodischarge diamond grinding (EDDG)

Electrodischarge diamond grinding (EDDG) is a hybrid machining process comprising conventional grinding and electrodischarge machining (EDM) as its constituent processes. It has the potential of shaping advanced engineering materials. Temperature of the workpiece and material removal rate are chosen as responses in full factorial (3³) design with current, pulse-on time, and wheel speed as process parameters. Specific energy is a vital consideration for any machining process. EDM is known for its inefficiency. Experiments were conducted with a specially fabricated bronze disk as tool electrode to evaluate specific energy in EDM, and the results were compared with that of EDDG. It has been found that specific energy required in EDDG is less than that in EDM with a rotating disk electrode.     

高精度硬质合金套类零件的加工方法

介绍硬质合金套类零件电解和电解磨削加工的基本原理,综合运用了以下多种新工艺:螺旋电极电解扩孔、螺旋 电极电解磨孔、中极法电解磨削外圆及端面。     

电火花特种加工技术及应用

电火花加工技术在制造业中占有很重要地位,是实现难加工材料、复杂零件精密加工的有效方法。本文重点介绍了电火花小孔磨削、电火花加工螺纹、电火花表面强化和刻字及深小孔电火花加工的原理、特点及应用。     

TEMPERATURE DISTRIBUTION DURING ELECTRO-DISCHARGE ABRASIVE GRINDING

The objective of this work is to develop a finite element method (FEM) based mathematical model to simulate the hybrid machining process of grinding and electric discharge machining (EDM), named as Electro-discharge abrasive grinding (EDAG), for temperature distribution in the workpiece. Two different finite element codes have been developed to calculate the temperature distribution due to grinding heat source and EDM heat source separately. The transient temperature field within workpiece due to cut-off grinding is determined due to moving rectangular heat source. Gaussian heat distribution of power within a spark has been considered in the calculation of temperature distribution due to EDM. Temperature distribution in the workpiece due to combined process is obtained by using superposition. The simulation shows a sudden rise in temperature at the spark location. The predicted results can be used for calculation of thermal stresses, which play a major role as far as high-quality product requirements are concerned.     

TEMPERATURE DISTRIBUTION DURING ELECTRO-DISCHARGE ABRASIVE GRINDING

The objective of this work is to develop a finite element method (FEM) based mathematical model to simulate the hybrid machining process of grinding and electric discharge machining (EDM), named as Electro-discharge abrasive grinding (EDAG), for temperature distribution in the workpiece. Two different finite element codes have been developed to calculate the temperature distribution due to grinding heat source and EDM heat source separately. The transient temperature field within workpiece due to cut-off grinding is determined due to moving rectangular heat source. Gaussian heat distribution of power within a spark has been considered in the calculation of temperature distribution due to EDM. Temperature distribution in the workpiece due to combined process is obtained by using superposition. The simulation shows a sudden rise in temperature at the spark location. The predicted results can be used for calculation of thermal stresses, which play a major role as far as high-quality product requirements are concerned.     

介入治疗用导丝的电火花加工工装设计

通过分析介入治疗用导丝的材料特性和结构特点,确定了导丝加工采用电火花磨削加工方法;从提高导丝加工的质量、自动化程度和效率方面考虑,对加工工装的关键部件和控制系统进行了详细设计;最终设计了一套专用的导丝电火花加工工装,为介入治疗用导丝的加工探索出了一种新的方法.     

Diamond face grinding of WC-Co composite with spark assistance: Experimental study and parameter optimization

Electro-discharge machining (EDM) characteristics of tungsten carbide-cobalt composite are accompanied by a number of problems such as the presence of resolidified layer, large tool wear rate and thermal cracks. Use of combination of conventional grinding and EDM (a new hybrid feature) has potential to overcome these problems. This article presents the face grinding of tungsten carbide-cobalt composite (WC-Co) with electrical spark discharge incorporated within face of wheel and flat surface of cylindrical workpiece. A face grinding setup for electro- discharge diamond grinding (EDDG) process is developed. The effect of input parameters such as wheel speed, current, pulse on-time and duty factor on output parameters such as material removal rate (MRR), wheel wear rate (WWR) and average surface roughness (ASR), are investigated. The present study shows that MRR increases with increase in current and wheel speed while it decreases with increase in pulse on-time for higher pulse on-time (above 100 μs). The most significant factor has been found as wheel speed affecting the robustness of electro- discharge diamond face grinding (EDDFG) process.