磨削参数对ELID内圆磨削轴承外圈的影响

从磨削过程中振动功率的角度研究了在线电解修整(ELID)内圆磨削轴承外圈时,磨削深度和砂轮进给速度对磨削表面波纹度的影响,并通过不同的磨削参数组合,从磨削过程中氧化膜状态和材料去除机理等角度分析比较了磨削深度和砂轮进给速度对磨削过程影响的程度。试验结果表明,磨削深度的作用更重要,在实际ELID内圆磨削过程中可以先采用较大的磨削深度以实现高的材料去除率,再采用较小的磨削深度以提高表面质量,并且在ELID磨削过程中可以通过振动的大小来预测加工后工件表面的波纹度大小。     

球轴承外圈沟道ELID成形磨削工艺参数优化

为了优化球轴承外圈沟道ELID(Electrolytic In?process Dressing)成形磨削工艺参数,通过多因素正交试验研究了ELID成形磨削过程中磨削参数和电解参数对砂轮磨损和工件表面粗糙度的影响规律,综合砂轮径向磨损量和工件表面粗糙度两个指标对磨削试验进行了综合评估.结果表明,磨削参数中的径向进给速度对砂轮径向磨损量的影响最大,砂轮转速对工件表面粗糙度影响最大;电解参数中的占空比对砂轮径向磨损量的影响较大,电解电压对工件表面粗糙度影响较大;砂轮转速为18000 r/min,工件转速为100 r/min,径向进给速度为1μm/min,占空比为50％,电解电压为90 V(6.7Ω)时,综合效果最优.     

ELID 磨削工艺控制研究

砂轮表面氧化膜的形成规律与特性对ELID超精密磨削质量有着重要的影响。研究在ELID磨削中氧化膜的形成规律,基于电化学基本原理,模拟砂轮表面氧化膜形成过程,并分析金刚石砂轮电解预修整过程中氧化膜的生长规律。在此基础上,总结出控制氧化膜生长的几个主要因素之间的关系,分析和确定氧化膜生长厚度与电压之间的关系,应用循环结构编程设计实现ELID磨削工艺控制。     

ELID磨削氧化膜控制方案的设计与研究

微处理器为处理控制单元,通过ELID精密磨削技术对金属基砂轮进行在线修整,改变砂轮氧化膜厚度,从而调整ELID磨削状态.该方案自动处理数据,判断磨削膜厚状态,改变电解电源参数,使砂轮始终保持锋利状态.此方法实现磨削过程无人控制,砂轮连续自动修整,消除传统磨削加工停机修整砂轮的弊端,提高磨削效率,减少砂轮过快损耗.     

在线电解修整磨削氧化膜研究现状及展望

在线电解修整（ELID）镜面磨削加工中,电解作用会使砂轮表面生成一层具有绝缘作用的氧化膜,该氧化膜可以减缓和阻止进一步电解,避免砂轮损耗过快;同时,氧化膜可容纳、承托大量因电解而脱落的磨粒,使得砂轮的磨削类同游离磨粒的研磨、抛光作用,有利于提高磨削表面质量。氧化膜在整个磨削过程中发挥着至关重要的作用,直接影响着ELID磨削加工表面质量和磨削效率。详细阐述了ELID磨削过程中氧化膜的成膜过程及表征方法、氧化膜的物理/化学特性、氧化膜成膜影响因素等方面的研究进展,并对ELID磨削氧化膜下一步的研究重点进行了展望。     

轴承钢内圆ELID磨削机理及工艺参数优化

针对轴承钢内圆传统磨削加工方式存在的精度低、烧伤及裂纹等缺陷,本文采用ELID精密镜面磨削技术对其进行试验研究。在ELID精密镜面磨削机理及钝化膜生成速率模型的理论指导下,通过采用二次通用旋转组合方法对影响轴承钢内圆表面粗糙度的各工艺参数进行ELID磨削试验设计。利用DPS数据处理系统软件对试验结果进行分析得到表面粗糙度二次回归数学模型及各工艺参数对表面粗糙度的单因素影响规律。利用Lingo软件优化得到轴承钢内圆ELID磨削最佳工艺参数为砂轮线速度30m/s、电解电压75V、电解间隙0.2mm、占空比50%,在此最佳工艺参数下,磨削轴承钢内圆可获得表面粗糙度为13nm的已加工表面。     

超声ELID复合内圆磨削时电参数对氧化膜的影响

通过Labview对试验中电压电流的测试,用VHX-2000超景深显微镜对氧化膜进行观测,分析了超声ELID复合磨削电参数与砂轮表面氧化膜之间的关系。研究结果表明,电参数的选择决定了砂轮结合剂发生电解反应溶解去除的速度以及砂轮表面生成氧化膜的厚度,进而影响砂轮的磨削性能和工件的磨削质量。     

电源参数对氧化锆ELID高速磨削表面粗糙度的影响

通过实验,分析了电源参数与氧化锆陶瓷ELID高速磨削表面粗糙度之间的关系。研究结果表明,电源参数的选择决定了砂轮结合剂发生电解反应溶解去除的速度以及砂轮表面生成氧化膜的质量,进而影响砂轮的磨削性能和工件的磨削质量。     

ELID磨削砂轮表面氧化膜状态的表征

在线电解修整磨削(ELID)是一种电化学加工技术,可在磨削过程中对铸铁基砂轮进行连续修整,非常适合硬脆材料的超精密镜面加工.在ELID磨削过程中,砂轮表面氧化膜的状态对ELID磨削影响重大,在磨削过程中维持良好的氧化膜状态是获良好表面质量的前提保证.本文通过粘附性实验,建立了氧化膜的状态归一化模型,利用在ELID磨削过...     

ELID 超精密磨削砂轮表面氧化膜形成过程的建模和仿真

砂轮表面氧化膜的形成规律与特性对ELID超精密磨削质量有着重要的影响。为了研究在ELID磨削中氧化膜的形成规律,基于电化学基本原理,建立了砂轮表面氧化膜形成过程的一般模型,并对金刚石砂轮电解预修整过程中氧化膜的生长过程进行了仿真。在此基础上,对控制氧化膜生长的主要因素进行了理论分析。为了验证模型和仿真结果的正确性,采用与仿真过程同样的控制参数,对氧化膜的生长特性进行了实验研究。结果表明仿真结果与实验结果基本吻合。     

Precision grinding of bearing steel based on active control of oxide layer state with electrolytic interval dressing

The oxide layer state directly relates to machining quality in electrolytic in-process dressing (ELID) grinding. In this paper, intermittent grinding control strategy was used to monitor and control the state of the oxide layer in interval ELID (ELID II) grinding. Some experiments were implemented based on active control of the oxide layer state. The influence of dressing current, wheel speeds, and grit size on surface roughness and waviness has been discussed in detail with ELID II grinding for bearing steel. The experimental results illustrate that the ELID II method can realize a stable grinding process based on active control of the oxide layer state. The surface roughness (Ra) and waviness (Wa) increase with increase of the dressing current. When the dressing current is constant, Ra and Wa reduce as wheel speed increases and decrease as grain size of wheel decreases. The experimental results also show that sufficient abrasive protrusion can be ensured in ELID II grinding, especially for grinding with a W2.5 super-abrasive wheel which may produce a very smooth surface quality, Ra 0.0166 μm and Wa 0.018 μm.     

Grinding of aluminium silicon carbide metal matrix composite materials by electrolytic in-process dressing grinding

The grinding cost of metal matrix composite materials is more due to low removal rates and high rates of wear of super abrasive wheels. This electrolytic in-process dressing (ELID) technique uses a metal-bonded grinding wheel that is electrolytically dressed during the grinding process for abrasives that protrude continuously from super abrasive wheels. This research carries out ELID grinding using various current duty ratios and conventional grinding of 10% SiC_p reinforced 2,124 aluminium composite materials. Normal forces and tangential forces are monitored. Surface roughness of the ground surface, Vickers hardness numbers and metal removal rate (MRR) are measured. The results show that the cutting forces in the ELID grinding are unstable throughout the grinding process due to the breakage of an insulating layer formed on the surface of grinding wheel and are less than conventional grinding forces. A smoother surface can be obtained at high current duty ratio in ELID grinding. The micro-hardness is reduced at high current duty ratio. In ELID, the MRR increases at high current duty ratio. The results of this investigation are presented in this paper.     

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.     

Deformation analysis of micro/nano indentation and diamond grinding on optical glasses

The previous research of precision grinding optical glasses with electrolytic in process dressing (ELID) technology mainly concentrated on the action of ELID and machining parameters when grinding,whic...     

基于多层钎焊金刚石砂轮在线电解修整技术的超细晶硬质合金精密磨削研究

利用模压成型技术和真空钎焊技术制备出了磨粒把持力大、力学性能优良的多层钎焊金刚石砂轮;采用在线电解修整技术促使磨钝的磨粒及时脱落,使砂轮在磨削过程中始终保持锋利性;并开展了基于多层钎焊金刚石砂轮在线电解修整技术的超细晶硬质合金精密磨削试验。试验结果表明：在相同磨削条件下,多层钎焊砂轮在线电解修整磨削力较无修整时的磨削力下降了33.7%～57.9%;多层钎焊砂轮在线电解修整磨削技术能有效提高加工表面质量。当进给速度为30 mm/s,磨削深度为15 μm时,无电解磨削加工表面粗糙度为0.35 μm,而在线电解修整磨削表面粗糙度仅为82.1 nm;多层钎焊砂轮在线电解修整磨削残余应力仅为无电解磨削时的38.2%～49.5%。且在线电解修整磨削表面完整性较好,没有出现表面/亚表面裂纹等相关缺陷,可实现超细晶硬质合金等难加工材料的高效精密加工。     

ELID磨削氧化膜厚度测量方法研究

在ELID磨削原理的基础上,分析了ELID磨削过程中氧化膜的生成和作用机理以及氧化膜的生长规律;综合评述了氧化膜厚度的离线测量方式以及用ELID磨削加工过程中的电压电流值的大小间接表征氧化膜的状态的最新进展。同时提出了基于LabVIEW开发平台,利用激光位移传感器和电涡流位移传感器的组合在线直接测量氧化膜的厚度的方法。