GCr15轴承钢的ELID超精密磨削工艺参数的优化研究

为探究GCr15轴承钢超精密加工的新途径,采用ELID精密镜面磨削技术对其进行试验研究。在ELID磨削原理及精密镜面磨削机理的指导下,采用二次通用旋转组合方法对影响GCr15轴承钢表面粗糙度的各工艺参数进行ELID磨削试验设计。首先利用DPS数据处理系统对试验结果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,然后利用lingo软件优化得到GCr15轴承钢ELID磨削最佳工艺参数为砂轮线速度26.41 m/s,电解电压90 V,电解间隙0.2 mm,占空比53.59%,并在此最佳工艺参数的基础上磨削GCr15轴承钢,获得表面粗糙度为14 nm的已加工表面。     

ELID镜面磨削硬质合金的工艺参数实验研究

随着国防尖端技术的迅速发展,许多具有独特性能的新材料得到了日益广泛的应用,如光学玻璃、硬质合金。但采用传统磨削工艺加工这些材料很难得到良好的表面质量。在线电解砂轮修整(ELID)磨削技术是一项新的、高效的磨削方法,它有效地实现了许多难加工材料的超精密加工和高效加工。针对硬质合金的特性,用ELID磨削方法应用于硬质合金的精密加工,通过实验研究ELID磨削中工艺参数对加工表面的影响规律,找到了在一定条件下优化的工艺参数。     

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。     

ELID精密镜面外圆磨削技术的应用

在线电解修整(ELID)精密镜面磨削有效地实现了许多难加工材料的平面精密加工和高效加工.本文介绍了ELID磨削技术在精密镜面外圆磨削上的应用.通过采用金属基超硬磨料砂轮在线电解修整对硬质合金、碳化硅陶瓷进行精密镜面外圆磨削,得到了表面粗糙度Ra=0.025～0.028μm的加工表面.     

硬质合金的ELID磨削试验研究

将ELID磨削方法应用于硬质合金的精密加工,通过试验研究ELID磨削中电解参数对加工表面的影响规律,找到了在一定条件下优化的电解参数。     

ELID精密镜面外圆磨削技术的应用

在线电解修整（ELID）精密镜面磨削有效地实现了许多难加工材料的平面精密加工和高效加工。本文介绍了ELID磨削技术在精密镜面外圆磨削上的应用。通过采用金属基超硬磨料砂轮在线电解修整对硬质合金,碳化硅陶瓷进行精密镜面外圆磨削,得到了表面粗糙度Ra=0.025-0.0028μm的加工表面。     

不同体积分数SiCp/Al复合材料精密磨削试验研究

对体积分数为40%和60%的SiC_p/Al复合材料进行ELID精密磨削试验。分析了体积分数对加工材料物理化学性能的影响;运用正交试验和极差分析方法探究了磨削深度、砂轮线速度、电解电流及占空比对磨削加工表面质量和精度的影响规律,并得到优化工艺参数。采用相同优化工艺参数,对不同体积分数SiC_p/Al复合材料进行ELID精密平面磨削试验,对所得到的加工样件表面质量、形貌和机械加工性能进行分析研究。试验结果表明:SiC_p/Al复合材料ELID精密磨削加工表面质量和机械加工性能随着体积分数的增加而降低。采用ELID磨削技术可以实现对SiC_p/Al复合材料的精密加工,加工样件的表面粗糙度为95nm和106nm。     

铝基金刚石精密磨削工艺实验研究

铝基金刚石新型复合材料是我国航天、电子封装等领域不可或缺的材料,但对其精密加工十分困难。采用ELID磨削技术对铝基金刚石进行精密磨削加工试验研究,探究不同磨削工艺参数对铝基金刚石加工表面质量的影响规律,并对各因素工艺参数进行优化。得出磨削深度9.3μm,砂轮线速度36 m/s,占空比63.7%电解电流11.5 A的最佳工艺参数组合,加工出表面粗糙度Ra=149 nm的表面。     

基于ELID磨削技术的轴承滚道切入式磨削加工工艺研究

针对高精度轴承滚道传统加工存在加工精度低、效率低、一致性难以保证等问题,采用ELID磨削技术对轴承内圈外滚道进行切入式磨削加工工艺试验研究。在ELID精密镜面磨削机理和单颗磨粒切入切出磨削模型的指导下,首先通过单因素试验法探究砂轮线速度、电解电流、电解间隙对轴承滚道表面粗糙度的影响规律,在此基础上利用正交试验法得到最优加工工艺参数组合:砂轮线速度46 m/s、电解电流6 A、电解间隙0. 2 mm,最后在最优加工工艺参数的指导下对轴承内圈外滚道进行ELID切入式磨削加工,获得表面粗糙度R_a为12 nm的表面质量。     

金刚石复合片ELID精密磨削工艺及机理研究

针对金刚石复合片的超精密加工难题,基于正交试验法优化金刚石复合片ELID精密磨削参数组合,采用极差分析得到了各因素对加工质量的影响程度大小,并以此为基础进行了工艺实验。根据金刚石复合片磨削加工后的SEM电镜扫描图,对其表面磨削机理及加工表面典型缺陷进行了分析。研究表明,金刚石复合片的ELID精密磨削最优参数为磨削深度为0.3μm、主轴转速1500r/min、占空比40%、工件移动速度为0.25mm/s、电解电压25V、电极间隙1mm。采用优化后的参数组合进行磨削加工,获得了粗糙度为0.019μm的加工表面。     

SUS304不锈钢ELID镜面磨削正交化实验研究

SUS304不锈钢具有高耐腐耐磨性和良好的综合性能而被广泛应用,但其高韧性和低导热性使传统的SUS304不锈钢磨削或车削工艺存在一定困难。在线电解修整ELID(Electrolytic in-process dressing)磨削技术能有效地用于SUS304不锈钢镜面磨削加工。本文主要对SUS304不锈钢进行ELID镜面磨削正交化实验研究以获得合理的工艺参数。首先利用#325砂轮进行7个影响因素2水平的正交磨削实验,获得初步的优化参数,然后利用#1200砂轮进行3个影响因素2水平的正交镜面磨削实验。通过改变削件砂轮转速、X和Y平台移动速度、进给率和ELID电源件等各种磨削条件,获得优化后的磨削工艺参数,进行了相应的磨削验证,并讨论了工艺参数对磨削特性的影响。研究了不同砂轮磨粒对表面粗糙度的影响,使用#8000金刚石砂轮对SUS304不锈钢镜面磨削,获得表面粗糙度Ra=3.6 nm。     

光学玻璃超精密镜面磨削表面质量影响试验研究

在线电解砂轮修整(ELID)磨削技术是一项新的、高效的磨削方法,可用于许多难加工材料的超精密加工和高效加工。采用ELID磨削方法对光学玻璃进行精密加工,通过实验研究了ELID磨削中电解电流和电压对加工表面的影响,得到了一定条件下优化的电解频率、电解电压参数。结果表明:在较高的电解频率下,加工工件的表面质量较好,但电解频率过高,表面质量会出现下降;加工工件的表面质量随着电解电压的增大有降低的趋势;在本文试验条件下,电解频率为100kHz,电解电压为60V时,加工表面质量最好。     

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.     

ELID磨削工艺参数对磨削力的影响

小口径非球面玻璃透镜因具有极高的成像质量和成像分辨率而被广泛应用于中高档镜头中。在线电解修整(Electrolytic In-Process Dressing,ELID)磨削作为高效的镜面磨削方法被广泛应用于硬、脆等加工材料的镜面磨削。在精密平面磨床上安装喷嘴电解ELID磨削系统对硬质合金材料进行了喷嘴电解方式ELID磨削试验研究。实验分析了磨削力随着砂轮转速、工作台进给速度、磨削深度三个磨削工艺参数变化的规律。同时,相同的磨削参数下,比较喷嘴电解方式ELID磨削和普通磨削的磨削力研究。试验结果表明,喷嘴电解方式ELID磨削能明显降低磨削力,与普通磨削相比较,能更好的实现硬质合金材料的超精密磨削加工。     

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.     

Experimental study of wheel wear in electrolytic in-process dressing and grinding

Profile accuracy of components ground with ultra-precision machine tools is primarily dependent on wheel wear. Quantitative analysis of wheel wear is therefore an important aspect for precision grinding with electrolytic in-process dressing (ELID). In this paper, wheel wear is measured from ELID grinding experiments with different dressing and machining parameters. The grinding forces and dressing current characteristics of the experiments are also compared. Based on the results, a benchmark function is defined for wheel wear rate. A relation for identifying insufficient dressing from sufficient dressing for particular machining conditions is also identified. It is found that insufficient dressing produces pitting and/or arcing on the wheel surface, and wheel wear can be linearly correlated to ELID grinding conditions when the wheels are sufficiently dressed.     

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。     

Efficient dressing of the wheel in ELID grinding by controllable voltage with force feed back

Electrolytic in-process dressing (ELID) grinding is a new method for achieving ultraprecision surface on hard and brittle materials. In ELID grinding, pulsed direct current voltage is applied on the metal-bonded diamond wheels to ensure constant protrusion of sharp cutting grits throughout the grinding cycle. The peak dressing voltage is kept constant irrespective of the wheel sharpness in conventional ELID grinding, which may lead to overdressing of the grinding wheel. Grinding force ratio (which is also known as K value) is an indicator for the grit sharpness. In this paper, a new approach of wheel dressing has been proposed where the peak dressing voltage is varied according to the change in the K value during grinding. A Kistler three-component dynamometer has been used to monitor the grinding force ratio in real time for this purpose. The methodology to implement the new “dressing-on-demand” concept has been discussed thoroughly in this paper. The experimental comparison with the conventional ELID grinding has also been carried out to prove the advantages of the proposed system.     

Cylindrical grinding of bearing steel with electrolytic in-process dressing

Cylindrical surfaces are increasingly utilized in various areas, and related high-efficiency and high-quality fabricating technologies are of great importance and significant benefit to modern industry. To provide fundamental knowledge for the bearing industry, studies have been conducted on the use of cast-iron-bonded cubic boron nitride (cBN) superabrasive wheels, based on electrolytic in-process dressing (ELID) technique for realizing high-efficiency grinding of steel cylindrical workpieces. Therefore, in this investigation, experiments were carried out on an ordinary cylindrical grinder with a hydrodynamic spindle, and straight type grinding wheels of different grit sizes were used. The effects of grit sizes on surface roughness as well as waviness, roundness, and surface stress were evaluated in both the traverse and plunge grinding modes. Comparison of ELID grinding with other processes was also carried out. Mirror surface grinding of different materials was achieved with the #4000 CIB-cBN wheel. ELID grinding was confirmed to induce compressive stress and to be more cost effective for small batch production of larger components when it works in the traverse mode.     

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。