共查询到18条相似文献,搜索用时 614 毫秒
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铁基金刚石钻头胎体配方的混料试验设计研究 总被引:1,自引:0,他引:1
为预测铁基金刚石钻头胎体配方中各混料因素的最佳配比,利用极端顶点设计和有约束的混料均匀设计两种试验设计方法,设计出胎体配方方案。计算结果表明:基于极端顶点设计的方案,试验点数较多,且多在试验边界上,分布不够均匀;基于有约束的混料均匀设计的方案,选用条件分步法产生均匀设计,生成的各试验点满足混料约束条件,在试验区域分布均匀,试验点数可预先确定,用较少试验点代表了较多试验信息,为开发新型金刚石钻头胎体配方提供了可靠的定量试验方法。 相似文献
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高速切削加工刀具材料 总被引:1,自引:0,他引:1
介绍了高速切削加工技术及模具高速切削所使用的陶瓷刀具、金刚石刀具、立方氮化硼刀具、涂层刀具的性能特点及应用,探讨了模具高速切削刀具材料的发展方向. 相似文献
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用热丝化学气相沉积法(hot filament chemical vapor deposition,HFCVD)制备金刚石涂层刀具时,衬底温度对金刚石涂层分布的均匀性有重要影响。利用仿真软件ANSYS中的FLUENT模块,对GAMBIT中建立的三维HFCVD批量刀具反应模型进行分析,并运用耦合热传导、热对流、热辐射等3大传热方式对该模型衬底温度分布情况进行仿真预测,对影响涂层分布均匀性的刀具底部支撑台材料散热方式进行分析、优化。仿真结果显示:相较于传统的铜质支撑台和石墨支撑台,热导率小的陶瓷材料支撑台的刀体平均温差最小,为37.82 ℃,比采用铜材料为支撑台时的刀体平均温差降低了45 ℃,更有利于制备膜厚、质量均匀的CVD金刚石涂层刀具。 相似文献
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金刚石在胎体中的分布形态对于金刚石工具的性能有着重要的影响。为了定量评价金刚石在胎体中的分布格局,本文在对金刚石钻头表面进行数字图像分析的基础上,采用锐角比率作为指标,对3个钻头中金刚石分布的均匀性进行了计算;并把它的计算结果与角度平均值法、最近距离法的结果进行了比较。实验结果表明:锐角比率法、角度平均值法和最近距离法都能反映各钻头的金刚石分布均匀程度的差异,但锐角比率法有一定的分类能力,区分度最好;角度平均值法和最近距离法都难以对金刚石分布格局进行准确分类。 相似文献
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在分析燃焰法民金刚石机理的基础上,研究了用燃焰法在刀具上沉积金刚石薄膜时的生长均匀性问题,提出了刀刃上金刚石的异常生长原因及抑制方法,获得了涂层均匀的金刚石薄膜涂层刀具。 相似文献
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采用超精金刚石刀具的超精加工是一种能实现纳米级尺寸精度及表面粗糙度的加工技术。最近,超精加工技术已在光电、生物领域用精密模具的加工中得到了应用。超精金刚石刀具是实现模具超精加工的关键要素之一。 相似文献
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In order to machine micro aspheric molds and dies made of ceramics, micro milling tools made of polycrystal diamond (PCD) are developed. Twenty cutting edges are ground and polished with diamond wheels and loose abrasives on the edge of a small cylindrical PCD tool shank. Some micro aspheric molding dies made of binder-less tungsten carbide were cut with the PCD milling tool developed. The molds and dies were cut in the ductile mode. The form accuracies of the micro aspherical mold and the micro lens array mold obtained were less than 100 nmP-V and the surface roughness 15 nmRz. 相似文献
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S.Y. Luo T.H. Yu C.Y. Liu M.H. Chen 《International Journal of Machine Tools and Manufacture》2009,49(3-4):212-219
The purpose of this paper was to investigate the wearing and grinding characteristics of the micro-abrasive pellet tools with 4–6 μm diamond particles fabricated by a LIGA-like process that has micro-lithography with photoresist mold and nickel/diamond composite electroforming. The results showed that when the micro-pellet tool containing partial resist joint with a root on the substrate was designed and fabricated, the tool against alumina sandpaper in wear test showed lesser amount of micro-pulled-out pellets than the tools with flat joint type, which displayed the tool to have better adhesion strength. In addition, when the micro-diamond tools were used to grind silicon wafers, the surface appearance of wafers showed ductile behavior. The surface roughness of wafers ground with increased pellet tool rotation speed became better and Ra=0.05 μm was achieved. 相似文献
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To fabricate three-dimensional microstructures, such as micro dimples, micro grooves and micro channels, on ceramic mold materials, tool fabrication with super hard materials is an essential step. In this work, micro electro discharge machining (EDM) was used to fabricate high-precision polycrystalline diamond end mills. Form accuracy and edge sharpness in one micron level were achieved by utilizing electro discharge induced graphitization of diamond grains under extremely low discharge energy conditions. The cutting performance of the fabricated tools was examined by machining micro dimples and micro grooves on tungsten carbide mold substrates. Results showed that using the EDM-fabricated tools, ductile mode machining of tungsten carbide was realized with a surface finish of 2 nm Ra, which is comparable to that produced by polishing. 相似文献
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有序排布和烧焊一体化制造金刚石工具新技术研究 总被引:3,自引:0,他引:3
本文主要介绍了两种制造金刚石工具的新技术:有序排布和烧焊一体化。有序排布技术是利用现代加工制造方法使得金刚石在其工具的表面排布达到规则化、序列化,从而减少重复磨损,延长工具的使用寿命以及提高加工对象光洁度的效果。现阶段,有序排布技术主要适用于小颗粒或微粉级的复制技术和大粒径金刚石的陶瓷孔模板技术。烧焊一体化技术则是采用直接加热均匀混合金刚石的烧结料粉到熔融状态,并在液态下直接焊接到钢基体上,从而避免了传统烧结金刚石工具的制造从混料、制模、冷/热压以及最后的完成工序等烦琐步骤,实现了烧结金刚石工具制造的“自动化”。 相似文献
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Polycrystalline diamond (PCD) micro-grinding tools are shaped by using different electro-discharge machining processes, among which wire electro-discharge grinding (WEDG) process is widely accepted due to its capability of producing highly precise, ultra-thin and dimensionally accurate tools. Observing the effects of different WEDG conditions on the tool surface and analyzing the tool's topographic features relevant to micro-grinding are of utmost importance. Current study deals with dressing of polycrystalline diamond tool blanks at different combinations of wire tension and discharge energy to observe the effects of dressing parameters on the tool surface morphology and statistics. Surface roughness, ridge type surface defects and diametrical error in the fabricated tool are analyzed with respect to discharge energy and wire tension. High wire tension produces tools with consistence surfaces and desired diameter. Binder material cobalt is efficiently melted and flushed out from the tool surface at high wire tension, which leads to proper segregation and protrusion of diamond abrasives from the surface. Static abrasive grit density measured by processing the 3D surface data of the tool is found to be ≈165–170 per mm, as compared to theoretically determined value of ≈200 per mm. Micro-slot grinding experiments are carried out on BK7 glass, to quantify the effects of the dressing parameters on the micro-grinding performances of the PCD micro-tools. Cutting forces for all the tools are found to be within 1 N whereas normal force exceeds beyond 1 N. Cutting forces are found to be higher for the tools dressed at high wire tension due to large diameter of the tool as compared to that of undersized tool obtained at low wire tension. Cutting nature is found to be mix of ductile-brittle for the machining conditions adopted in this paper. 相似文献
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Shun-Tong Chen Ming-Yi Tsai Yun-Cheng Lai Ching-Chang Liu 《Journal of Materials Processing Technology》2009,209(10):4698-4703
This study presents a novel micro-diamond tool which is 100 μm in diameter and that allows precise and micro-grinding during miniature die machining. A novel integrated process technology is proposed that combines “micro-EDM” with “precision composite electroforming” for fabricating micro-diamond tools. First, the metal substrate is cut down to 50 μm in diameter using WEDG, then, the micro-diamonds with 0–2 μm grain is “plated” on the surface of the substrate by composite electroforming, thereby becoming a multilayer micro-grinding tool. The thickness of the electroformed layer is controlled to within 25 μm. The nickel and diamond form the bonder and cutter, respectively. To generate good convection for the electroforming solution, a partition designed with an array of drilled holes is recommended and verified. Besides effectively decreasing the impact energy of the circulatory electroforming solution, the dispersion of the diamond grains and displacement of the nickel ions are noticeably improved. Experimental results indicate that good circularity of the diamond tool can be obtained by arranging the nickel spherules array on the anode. To allow the diamond grains to converge toward the cathode, so as to increase the opportunity of reposing on the substrate, a miniature funnel mold is designed. Then the distribution of the diamond grains on the substrate surface is improved. A micro-ZrO2 ceramic ferrule is grinded to verify the proposed approach. The surface roughness of Ra = 0.085 μm is obtained. It is demonstrated that the micro-diamond grinding tool with various outer diameters is successfully developed in this study. The suggested approach, which depends on machining applications, can be applied during the final machining. Applications include dental drilling tools, precision optic dies, molds and tools, and biomedical instruments. 相似文献
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Zone-Ching Lin Chia-Chin Liu 《International Journal of Machine Tools and Manufacture》1996,36(1):73-88
An orthogonal cutting model for finish machining, using diamond and tungsten carbide tools which have different coeffficients of thermal conductivity, was simulated and analyzed. It was assumed that the tool had a minute amount of tool flank wear. The distribution of strain rate and stress within the machined workpiece and the determination of the cutting force were obtained after simulation. The generation and distribution of temperature and stress within the chip through cutting of the workpiece were also acquired. In addition, the temperature of the tool, the workpiece and the chip during finish machining by the two different tools, that show the effects of the different friction coefficients of the diamond tool and the tungsten carbide tool on cutting, were compared. Finally, the cutting forces predicted by the model for orthogonal finish machining were compared with those obtained by experiment, and it appears that the present orthogonal finish machining model is reasonable. 相似文献