声光调QNd:YAG脉冲激光修锐金属结合剂金刚石砂轮

金属结合剂金刚石砂轮具有良好的磨削性能，在初次使用和磨损后必须对其修锐。由于金属结合剂和金刚石磨粒之间存在热物理、光学性质差异，可通过选择合理的脉冲激光功率密度去除结合剂，凸出磨粒，实现选择性去除。本文采用声光调QNd：YAG脉冲激光径向辐射，对金属结合剂金刚石砂轮进行修锐试验研究，并与传统机械修锐和连续激光修锐进行了比较。理论分析了声光调Q脉冲激光修锐金属结合剂金刚石砂轮的机理，试验研究了单脉冲激光烧蚀凹坑和脉冲激光修锐的情况，总结出激光、工艺参数对修锐效果的影响特点和规律。激光平均功率(Pm)增加、脉冲重复频率(f)减小、离焦量(Z)减小，则脉冲功率密度增加，凹坑深度增加。在本试验条件下，选择Pm=10W、f=5—8kHz、Z=0．0mm；Pm=20W、f=1—2kHz、Z=1．5mm和Pm=30W、f=1-2kHz、Z=3．0mm这些参数修锐，能获得较好的地形地貌。试验证明，以单脉冲试验为指导，合理选择激光参数进行修锐，可以得到较好的地形地貌。     

超硬磨料砂轮修整与激光修整新进展

本文介绍了超硬磨料砂轮修整的现状和特点，指出超硬磨料砂轮修整的关键和亟待解决的问题。重点介绍一种很有前途的修整技术－－激光修整，分析了其国内外近年来的研究情况。作者用声光调QYAG激光对树脂结合剂CBN砂轮进行了修锐试验，得出了声光调QYAG激光适宜修锐树脂结合剂砂轮的结论。对今后的超硬磨料砂轮激光修整的发展方向作了展望；建立材料热去除模型和气体动力学模型，完善激光修整机理的研究；实现激光整形和修锐过程同时进行；深入研究激光精密修整技术；开发成形砂轮激光修整技术；开发自适应控制修整系统，实现激光在线修数；提高修整效率。     

电火花修锐对金属结合剂CBN砂轮表面形貌的影响

采用电火花修锐方法对青铜结合剂锯齿形CBN砂轮在平面磨床上进行修锐实验,对修锐前后的砂轮表面形貌进行观测,修锐后砂轮的有效磨粒数、磨粒凸出高度明显增加,修锐时间以4~6h为宜;采用修锐后的砂轮对材料2T8/SK5进行了锯齿磨削加工实验,经测量,锯齿角度轮廓精度有较大提高。电火花修锐方法适合于金属基CBN砂轮的修锐。     

金属基金刚石砂轮的电火花修锐机理

对电火花放电作用下砂轮表面结合剂材料的去除机理进行了分析.在电火花成形机床上进行电火花修锐青铜结合剂金刚石砂轮的试验,在VH-800三维数字显微镜观察电火花修锐前后金刚石砂轮表面的微观形貌,考察了砂轮修锐前后表面峰点高度分布的变化,比较了不同放电参数作用下的修锐效果.实验证明电火花放电技术可应用于金刚石砂轮的修锐,电火花放电对金属结合剂金刚石砂轮进行修锐时存在一个合适的修锐参数范围,在这个范围内,修锐可以获得较好的效果.     

基于CNN的金刚石砂轮激光修锐参数优化

采用正交试验法对青铜金刚石砂轮进行激光修锐试验,并对其激光修锐参数进行优化。通过卷积神经网络（convolutional neural network,CNN）对砂轮表面图片进行像素级的金刚石磨粒识别,提取磨粒面积信息,求出磨粒突出高度,利用统计分布规律得到突出高度得分和最佳区间比率2个激光修锐质量评价指标。利用提出的评价指标对试验得到的砂轮激光修锐图片进行质量评价,并进行极差分析。结果表明:平均功率是影响修锐质量最大的因素。最优的修锐工艺参数为:平均功率,35 W;重复频率,100 kHz;转速,300 r/min;扫描速度,1.0 mm/min。      

树脂结合剂CBN砂轮修整的研究

该文研究了树脂结合剂CBN砂轮的修整,找出了一种简便的方法——磨削法,用GZ46ZR_1砂轮进行湿修锐,切入速度Vr=0.09mm/min,修锐约10分钟,取得了好效果。     

金刚石微粉砂轮软弹性修整研究（Ⅴ）──软弹性修锐

本文讨论软弹性修整法用于金属结合剂金刚石微粉砂轮修锐的修锐效果及修锐参数选择，并从微观的角度对软弹性修锐过程及修锐后砂轮表面形貌进行了分析。     

金刚石微粉砂轮软弹性修整研究（V）：软弹性修锐

本文讨论软弹性修整法用于金属结合剂金刚石微粉砂轮修锐效果及修锐参数选择，并从微观的角度对软弹性修锐过程及修锐后砂轮表面形貌进行了分析。     

ELID镜面磨削用铸铁超硬砂轮的精密整形与电解预修锐的质量评价

本文介绍了铸铁结合剂金刚石/CBN砂轮的精密整形技术及其在电解修锐中的问题,并对影响修锐质量的因素作了分析研究,并经试磨对ELID磨削装置、电源、电解液的质量性能作了验证。     

激光在磨削加工中的应用现状分析及试验研究

本文阐述了激光技术在磨削加工不同方面的应用情况。首先介绍了利用激光对工件表面进行改性处理以改善工件磨削加工性能以及激光辅助磨削硬脆材料的原理和方法。然后通过试验研究,着重阐述了激光在砂轮修锐以及检测砂轮表面形貌两方面的应用。试验结果表明,利用激光扫描方法可快速精确地测量砂轮表面的原始三维形貌,对砂轮工件性能作出客观评定,利用该方法可望实现砂轮形貌的在线检测;利用激光修锐砂轮,不仅可大大降低砂轮损耗,并且能精确控制修税效果,因而是一种很有前途的砂轮修锐方法。     

改变立方氮化硼磨具修整方向的研究

树脂结合剂CBN磨具的磨削性能取决于磨具的修整效果,磨具修整的效果关键在于其修整方向。本丈通过不同的修整方向的对比试验和磨削试验,分析用不同的修整角所修整出的磨具表面,找出了CBN磨具修整的最佳方法。     

A study on laser touch dressing of electroplated diamond wheels using pulsed picosecond laser sources

An investigation to explore the possibility of touch dressing of electroplated diamond wheels using a pulsed picosecond laser (ps-laser) beam (Yb:YAG) is presented. The laser beam is irradiated on the wheel to cut the diamond grains within a defined grain protrusion without any thermal damage on the nickel bond. The laser parameters were systematically varied to achieve a reliable touch dressing process. The microscopic investigations prove thermal damages neither on the diamond grain nor on the bond. Series of SiC wheel dressing experiments were carried out to compare mechanical touch dressing of the electroplated diamond wheel with laser dressed wheels.     

Dressing and truing of hybrid bonded CBN grinding tools using a short-pulsed fibre laser

This paper presents the results of an investigation into the dressing and truing of hybrid bonded (metal-vitrified) CBN grinding wheels using a short-pulsed fibre laser. Truing of complex contours on CBN grinding tools with sharp edges (edge radii of less than 20 μm) could be successfully applied, whereas other dressing methods have been neither technically nor economically successful. Sharpening by laser can provide the same wheel surface topography which is conventionally produced by SiC and/or Al₂O₃ sharpening tools. Grinding characteristics and long-term performance of the laser-profiled tools are discussed.     

Modelling and analysis of pulsed Nd:YAG laser machining characteristics during micro-drilling of zirconia (ZrO2)

Pulsed Nd: YAG laser beam has great ability for micro-machining of ceramic materials because of high laser beam intensity at low mean beam power, good focusing characteristics due to very small pulse duration, small kerf widths and narrow heat effected zones. In the paper, experimental investigations into CNC pulsed Nd:YAG laser micro-drilling of zirconium oxide (ZrO₂) have been carried out. Influence of laser machining parameters on the HAZ thickness and phenomena of tapering of the machined micro-holes has been experimentally investigated. Response Surface Methodology-based optimal parametric analysis has been performed to determine the optimal setting of process parameters such as pulse frequency and pulse width, lamp current, assist air pressure for achieving minimum HAZ thickness and taper of the micro-hole machined by pulsed Nd:YAG laser. Minimum HAZ thickness has been obtained as 0.0675 mm when the lamp current, pulse frequency, assisted air pressure and pulse width are set at optimal parametric setting i.e. 17 amp, 2.0 kHz, 2.0 kg/cm² and 2% of the duty cycle, respectively. Minimum taper has been achieved as 0.0319 at optimal parametric setting i.e. the lamp current of 17 amp, pulse frequency of 2.0 kHz, assisted air pressure of 0.6 kg/cm² and pulse width of 2% of the duty cycle. Analysis has also been carried out for multi-optimisation of both the responses i.e. HAZ thickness and taper during pulsed Nd:YAG laser micro-drilling on ZrO₂.     

GMAW电弧对Nd:YAG激光传输的影响

针对脉冲过渡熔化极气体保护焊(gas metal arc welding,GMAW)电弧和短路过渡GMAW 电弧,通过保持 GMAW 电弧正常态,Nd:YAG 激光水平逐层、逐点扫描穿过脉冲电弧区域的试验方式,获得了Nd:YAG 激光穿过GMAW 电弧后的激光折射和散射结果.试验发现,波长为1.064μm的Nd:YAG激光穿过脉冲GMAW 电弧激光光斑会略微变小,并且不同电弧区域对激光的影响能力基本相同;激光穿过短路GMAW电弧后激光光斑也会略微变小,不同电弧区域对激光的影响也基本相同.结果表明,GMAW电弧可以近似看作各项同性的激光传输介质,还可以近似认为GMAW电弧对波长1.064μm的Nd:YAG激光是透明的.

Abstract：

By keeping gas metal arc welding(GMAW)arc normal position and Nd: YAG laser parallel crossing GMAW arc,refrangibility of GMAW arc to Nd: YAG laser was measured.The results indicate that when Nd:YAG laser crosses pulse GMAW arc,laser radius will decrease slightly.And the influence of pulse GMAW arc of different part to Nd : YAG is almost same.Similarly,when Nd: YAG laser crosses short-circuiting pulse GMAW arc,the radius of the laser will decrease slightly too.By considering this phenomenon from welding point of view,GMAW arc can be regarded as transparent substance and optic isotropy to Nd:YAG laser.     

CBN磨料特性对树脂砂轮磨削性能的影响

对6种不同CBN磨料的静压破碎负荷、冲击韧性（TI）和热冲击韧性（TTI）的数据进行分析研究,并分别制作成树脂结合剂砂轮。针对不同材料工件进行磨削,研究不同CBN磨料制作的砂轮磨削铸铁、高速钢、不锈钢和氮化不锈钢等材料的磨削比。实验结果表明:同样结合剂和工艺条件下,不同CBN磨料制作砂轮的磨削比相差较大;树脂CBN砂轮对铸铁和高速钢材料的磨削比相对较高,但对不锈钢和氮化不锈钢材料的磨削比低;CBN-B1500和CBN850磨料对几种工件材料的磨削性能相对较好。树脂CBN砂轮中磨料靠结合剂机械嵌合力把持,因此具有粗糙表面和适中静压破碎负荷的CBN磨料是较优选择。      

激光表面微织构工艺试验及应用研究

在声光调Q二级管泵浦固体光源Nd:YAG激光器基础上,采用"单脉冲同点间隔多次"激光微加工工艺,对45#钢试样表面进行激光微织构加工。分析了离焦量、泵浦电流、重复频率及重复次数对微织构形貌的影响规律。工艺试验表明,微凹腔的直径和深度随着泵浦电流的增大而增大,随着重复频率的增加呈减小的趋势,微凹腔深度随脉冲次数的增加呈近似线性增加,而微凹腔直径呈缓慢减小趋势。通过对某型号四缸汽油机的台架性能试验研究,表明与传统平顶机械珩磨相比,采用激光珩磨技术的汽油机机油耗要比原机降低56%,燃油耗降低1.94%~4.5%。     

Temperatures and wear mechanisms in dressing of vitrified bonded grinding wheels

For the first time dressing temperatures were measured directly in the contact zone of grinding and diamond dressing tool. With average temperatures of 400 °C and maximum temperatures of 810 °C without cooling lubricant, the need to cool the dressing tool sufficiently is affirmed. For a diamond dressing tile and form rollers in contact with vitrified bonded corundum and CBN wheels, the main grit wear mechanisms were adhesions instead of breakage or high volumetric splintering. Extensive analyses proved that components of the grinding wheel bonding and abrasives were molten during the dressing process and solidified amorphously. This verifies high peak surface pressures and flash temperatures.     

金刚石砂轮精密修整工艺研究

金刚石砂轮机械磨削是砂轮整形的传统方式。砂轮旋转速度以及工具砂轮的进给量是金刚石砂轮机械精密整形的主要工艺参数。通过在超硬材料砂轮整形机床上的大量实验和砂轮磨削力的分析,得到了金属结合剂和树脂结合剂金刚石砂轮精密整形的比较理想的工艺参数;确定了工具砂轮的线速度应在11 m/s左右,工具砂轮轴转速在1 050～1 800 r/min;金刚石砂轮轴转速设定在400～1 000r/min,金刚石砂轮的线速度为2.6～10.5 m/s。同时,分析比较了机械修锐和喷砂修锐的效果。