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金属基超硬磨料砂轮耐磨及刚性好,但整形、修锐困难。本文介绍对金属基超硬砂轮的电火花修整、接触式电火花放电修整及电解放电修整,并着重介绍电解-机械循环复合精密修整技术。机械修锐金属基砂轮.磨料后面留有隆起的金属形成磨粒尾部,在磨削时会增加磨粒的粘附强度,可防 相似文献
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由于超硬磨料砂轮的磨削力大,因此应该采用刚性高的磨床。超硬磨料砂轮磨削的对象大多是难磨削材料,因此,磨削力比较大。由于超硬磨料砂轮具有修整时间间隔长,工具管理容易等优点,所以现在也正逐步用于易加工材料的磨削。但人们同时也把磨削力大这个特定现象当作普遍现象,从而认为超硬磨料砂轮摩削易加工材料时磨削力也大。 笔者认为,磨削力的大小由磨粒切削刃的几何学形状及其在砂轮表面的分布决定。磨粒的材质只影响砂轮的耐用度。超硬磨料砂轮磨削力大这个误解究竟是怎样产生的呢,本文主要阐述这个问题。 一、整形和修锐 超硬磨料砂轮的… 相似文献
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针对粗粒度超硬磨料砂轮圆跳动难以检测技术问题,提出一种新的砂轮圆跳动检测方法,利用滑块组件与激光位移传感器有机结合,避免了砂轮表面高硬度磨料和粗糙形貌对传统量仪触头的机械干扰,排除了砂轮表面非均质材料及高陡坡磨粒的光学干扰,可实现粗粒度超硬磨料砂轮圆跳动的真实、稳定、高效、高精检测。在CNC8325数控外圆磨床上对粒度60#/70#电镀CBN砂轮进行了精密修整试验,依据"定量修整-砂轮检测-定量磨削-试件检测"循环测试方案,持续跟踪了电镀CBN砂轮圆跳动、磨削功率、试件表面质量、砂轮表面形貌渐变过程。结果表明:当电镀CBN砂轮初始圆跳动在10~20μm时,砂轮已具有良好的综合磨削效果,可以不修整或微量修整;当砂轮表面高点区域部分磨粒去除量在磨料平均直径1/5以内时,仍可通过精密修整获取理想的砂轮表面;当砂轮表面高点区域部分磨粒去除量达1/4以上时,即使修整后砂轮圆跳动很好,也无法获得较好磨削效果,此时砂轮已不具备磨削能力。 相似文献
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针对空心球形复合超硬磨料的多微孔结构对磨削温度影响问题,研究了空心球形复合超硬磨料的结构,建立了空心球形磨料砂轮的磨削模型.从理论上分析了多微孔结构对砂轮的切削锋利度和携带冷却液能力的影响机制;运用温度测量系统,进行了陶瓷空心球形复合超硬磨料砂轮在不同磨削切深和不同冷却液供给量条件下的平面磨削温度实验研究,并分析了磨削温度随不同切深和冷却液供给量的变化趋势.研究结果表明,空心球形磨料砂轮的磨削温度明显低于传统超硬磨料砂轮,验证了空心球形磨料砂轮具有较锋利的切削刃和更好的携带冷却液能力,可有效降低磨削温度,是实现低温磨削的一种新途径. 相似文献
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E.-S. Lee 《The International Journal of Advanced Manufacturing Technology》2000,16(11):814-821
In recent years, grinding techniques for precision machining of brittle materials used in dies, moulds and optical parts have
been improved by using superabrasive wheels and precision grinding machines. Optimum dressing using a superabrasive wheel
makes possible the effective ultraprecision grinding of die steel (STD-11). In this study, a new system and the grinding mechanism
for optimum in-process electrolytic dressing are proposed. This method can carry out optimum in-process electrolytic dressing
of a superabrasive wheel. Optimum in-process electrolytic dressing is a good method for obtaining efficiency and ultraprecision
grinding of STD-11. 相似文献
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Single crystal MgO is widely used in material with high temperature resistance, but is difficult to grind because of brittleness and crack generation. Therefore, a diamond wheel with superabrasive surface is required for surface grinding of this material. But the conventional dressing method cannot be applied to the diamond wheel with superabrasive. This study describes a newly proposed method for carrying out effective in-process electro-discharge dressing (IEDD) of a diamond wheel with superabrasive. Using IEDD, the surface roughness of single crystal MgO was improved, the grinding force was very low and crack generation was reduced. IEDD is a good method to obtain efficient grinding and surface grinding of single crystal MgO. 相似文献
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Jeong-Du Kim Eun-Sang Lee 《The International Journal of Advanced Manufacturing Technology》1999,15(9):615-623
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. 相似文献
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E-S. Lee 《The International Journal of Advanced Manufacturing Technology》2000,16(5):314-321
Ferrite is widely used as a material for magnetic heads for hard disks, but it is difficult to grind because its high hardness
and brittleness. Therefore, a superabrasive diamond wheel is used for precision surface grinding of this material. However,
the conventional dressing method cannot be applied to a superabrasive diamond wheel. This study describes a new method for
carrying out effective in-process electro-discharge dressing (IEDD) of a superabrasive diamond wheel. Using IEDD, the surface
roughness of the Mn-Zn ferrite was improved, and the grinding force was reduced. IEDD is a good method for obtaining efficient
surface grinding of ferrite. 相似文献
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Professor Jeong-Du Kim Eun-Sang Lee 《The International Journal of Advanced Manufacturing Technology》1996,12(4):246-254
Fine ceramics have the properties of high hardness, chemical inertness, high thermal resistance and low electrical conductivity, but, because of high hardness and brittleness, they are very difficult to machine. Therefore, a superabrasive diamond wheel is used for mirror-like grinding of this material. In this study, an in-process electrolytic dressing system for carrying out mirror-like surface grinding was constructed. Using this system the grinding force for fine ceramics was reduced. This work shows that the application of electrolytic dressing is beneficial in obtaining a mirror-like surface when grinding fine ceramics. 相似文献
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A study on wear mechanism and wear reduction strategies in grinding wheels used for ELID grinding 总被引:3,自引:0,他引:3
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. 相似文献
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基于气中放电辅助修整金刚石砂轮的试验研究 总被引:1,自引:0,他引:1
提出了一种新型的基于气中放电辅助金刚石砂轮在线修整法,它把气中火花放电修整法和金刚石笔机械修整法有机结合在一起,能实现光学曲线磨床上金刚石砂轮的高效、高精度、低成本和不得使用任何冷却液的在线修整。采用自制的试验装置在MK9025数控光学曲线磨床上对1A1/T2 200×6×32×4 MBD6 120/140 M75型号的砂轮进行了在线修整试验,得出了一些影响金刚笔磨损率的主要因素:火花放电时热源的能量分布状况、金刚石笔修整时的修整深度、进给量以及电源电压。相同工况下机械修整法和气中放电辅助修整法中金刚石笔的磨损率对比试验结果表明:气中放电辅助修整和机械修整有着不同的材料去除机理,它比一般机械修整更有利于提高金刚石砂轮的修整效率和降低金刚石笔的磨损量。磨削YG8硬质合金工件的试验表明,采用气中放电辅助法修整的金刚石砂轮和新的金刚石砂轮有着相近的磨削能力。 相似文献