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1.
本文主要研究PCD刀具加工有色金属时刃口及后刀面的刃磨质量对切削表面质量的影响。首先对PCD刀具切削有色金属模型进行了分析研究,然后分别采用金属结合剂金刚石砂轮、树脂结合剂金刚石砂轮和陶瓷结合剂金刚石砂轮刃磨出三把不同质量的PCD刀具进行了切削对比试验,并用扫描电镜对切削表面微观形貌进行了观察分析,发现加工有色金属时,PCD刀具后刀面与刃口刃磨质量对切削表面质量有着同等重要的影响作用。 相似文献
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The production of extremely thick silicon carbide (SiC) has recently become possible with the advent of a specific chemical vapor deposition process. Ultra-precision machining of high-purity SiC has been performed by using a polycrystalline diamond (PCD) micromilling tool to investigate the machining characteristics. Results indicate that a high-quality surface (Ra = 1.7 nm) can be obtained when the removed chips are thin enough to achieve ductile mode machining. Micron-sized wells and groove structures with nanometer-scale surface roughness were successfully machined by using the PCD tool. In addition, a new electrochemically assisted surface reconditioning process has been proposed to remove the contaminant material adhered onto the PCD tool surfaces after prolonged machining. 相似文献
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本文对PCD磨削加工工艺进行了试验。结果表明:在进行PCD粗加工时,宜选用粗粒度、高强度金刚石磨料和采用较大的磨削压力。 相似文献
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切削参数是影响PCD刀具切削性能的主要因素。本文采用Element Six公司的SYNDITE CTH025型聚晶金刚石(PCD)复合片制成强化复合地板用切削刀具,进行了一系列加工强化复合地板耐磨层的切削实验。通过实验研究了切削参数对刀具切削力的影响,得出了切削力随切削参数的变化规律,指出随着切削深度的增加,PCD刀具切削力增加;进给速度的增加使切削力增加;切削速度的增加将会使切削力降低。同时,分析了切削参数对刀具磨损、工件加工质量以及加工效率的影响。最后,本文总结了采用PCD刀具加工强化复合地板时加工参数的选择原则,认为当n=6000r/min、f=10000mm/min能够实现较高的加工效率,并保证工件的加工质量。 相似文献
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本文研究制备Na2O-B203-Si02-Al203多元系基玻璃料,并配制成低温陶瓷结合剂,研究发现:耐火度为685℃,流动性为110%~130%,线膨胀系数为5.35×10-6℃-1的低温陶瓷结合剂具有优异的性能.制备的陶瓷结合剂金刚石砂轮在725℃烧成后,磨具的抗弯强度和洛氏硬度达到最佳值,分别58.61 MPa和77.9.用其磨削PCD刀片时锋利性好,磨削中间不需修整,砂轮耐用度高.运用扫描电子显微镜(SEM)分析了陶瓷结合剂金刚石磨具的断面形貌、磨削后磨削面形貌,表明结合剂对磨粒黏结牢固,断面组织均匀. 相似文献
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选取几种典型的PCD、PCBN复合片,在慢走丝电火花线切割机床上对其进行了多次加工工艺试验;运用三维表面轮廓仪、超景深三维显微镜对线切割加工后的表面粗糙度、富钴界面层加工质量、刃口加工质量等进行测量。结果表明:超硬颗粒直径大小及含量对加工质量影响较大,PCD、PCBN复合片经多次电火花线切割加工,能够得到较好的加工质量;经WEDM加工后的PCD复合片刃磨量可控制在4~15μm左右,PCBN复合片BNX20刃磨量可控制在10μm以内,而BZN6000则需较大的刃磨量。 相似文献
7.
聚晶金刚石复合片钎焊基础研究 总被引:2,自引:0,他引:2
通过对聚晶金刚石(PCD)复合片的热稳定性研究,总结出其钎焊的安全温度:在空气气氛下,钎焊SYNDITE PCD复合片时,CTB002的钎焊安全温度应低于650℃,CTB010应低于670℃,CTB025应低于720℃。在钎焊安全温度范围内通过四种钎料(编号1^#-4^#)对硬质合金的润湿性试验,优选出PCD复合片与硬质合金之间实施钎焊的最佳钎料为3^#(Ag50%,Cu15.5%,Zn15.5%,Ni+Co3%,Cd16%),其他钎料对硬质合金的润湿性明显低于3。。另外通过分析硬质合金中不同成分(碳化物WC、TiC、TaC、NbC和粘结剂Co)的钎焊性能,总结出钎焊PCD复合片应选用Co含量高的WC基硬质合金。 相似文献
8.
影响PCD刀具刃磨质量因素研究 总被引:4,自引:1,他引:3
本文采用合理的腐蚀清洗方法对PCD试样进行腐蚀,获得了清晰真实的PCD磨削表面。在此基础上借助扫描电镜,通过观察PCD刀具磨削表面和刃口的微观形貌,系统研究了磨床转速、磨削压力及磨削液等因素对PCD刀具刃磨质量的影响。研究结果表明:磨床转速越高,磨削表面质量越好,但过高或过低的转速会使刃口锯齿度增大;较大的磨削压力对磨削表面质量和刃口质量都有负面影响;同时,无论转速高与低,磨削压力大或小,干磨后的PCD磨削表面质量均好于湿磨。细砂轮低速干磨PCD时,磨削表面由于疲劳应力的作用出现了一些垂直于磨削表面的裂纹。 相似文献
9.
通过PCD刀具切削天然大理石的试验研究,分析了在不同加工参数条件下对PCD刀具切削性能的影响以及刀具的磨损机理。试验结果表明:PCD刀具在加工过程中的磨损机理主要表现为磨粒的磨损、剥落,聚晶层的破损与结合剂破坏等;刀具主轴转速为12 000 r/min、进给速度为1 000 mm/min、切削深度为0.5 mm时,刀具的磨损量最小;且磨损量随刀具主轴转速的增加而降低,随刀具的进给速度和切削深度的增加而增加。 相似文献
10.
目的:研究金刚石涂层立铣刀和 PCD 立铣刀切削铝合金时,铝合金表面粗糙度以及刀具的使用寿命。方法通过实验比较1μm、5μm金刚石涂层四刃立铣刀和PCD立铣刀在高速干式切削条件下切削铝合金的性能,并通过走刀距离比较不同状态刀具的使用寿命以及在走刀过程中的粘刀情况,用表面粗糙度测量仪测量加工的铝合金表面粗糙度。结果1μm、5μm金刚石涂层立铣刀加工铝合金失效距离分别为25 m、75 m, PCD立铣刀加工铝合金96 m后失效;1μm、5μm金刚石涂层立铣刀切削铝合金表面粗糙度平均值分别为1.07μm、1.10μm,PCD立铣刀切削铝合金表面粗糙度平均值为0.80μm。结论5μm金刚石涂层立铣刀是1μm金刚石涂层立铣刀寿命的5倍,PCD立铣刀使用寿命最长;1μm、5μm金刚石涂层立铣刀切削铝合金表面较PCD立铣刀粗糙,在相同切削环境下切削铝合金时, PCD立铣刀使用寿命较金刚石涂层立铣刀提高,且在抑制粘刀方面效果十分明显。 相似文献
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依据位错理论,建立了聚晶金刚石(polycrystalline diamond,PCD)离散位错动力学-有限元耦合的压痕仿真模型。通过离散位错动力学仿真,获得了在微压痕作用下PCD的位错云图,揭示了金刚石微粉颗粒尺寸及颗粒体积分数对聚晶金刚石压痕特性的影响规律,并分析了聚晶金刚石的位错演化机制及其失效行为。研究结果表明:采用离散位错动力学分析方法能够准确描述PCD的位错运动过程,PCD微粉颗粒尺寸增加会增大晶体位错滑移程度,金刚石颗粒体积分数增加则导致位错形核密度增加,最终将引起聚晶金刚石材料断裂强度下降。将离散位错理论引入到为分析聚晶金刚石位错演化的行为中,将为研究PCD在切削刀具等工程应用中材料的失效行为提供理论基础。 相似文献
13.
以Li2O-Al2O3-SiO2-B2O3系作为基础玻璃,设计了两种不同化学组成的结合剂(V1和V2)。采用三点弯曲法,考察了两种结合剂试样的抗折强度随烧结温度的变化规律,以及结合剂引入量对含金刚石试样抗折强度的影响;借助XRD衍射分析技术测试了结合剂试样条的物相构成;分别用两种结合剂制作了陶瓷结合剂金刚石砂轮,考察了在不同磨削条件下的磨削效果。实验结果表明:V1结合剂为玻璃质结合剂,V2结合剂为微晶玻璃质结合剂;采用V1结合剂制作的金刚石砂轮比采用V2结合剂制作的金刚石砂轮性能更佳,可用于PCD/PCBN复合片的粗磨加工。 相似文献
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刘於勋 《金刚石与磨料磨具工程》2008,(6)
聚晶金刚石刃磨工艺参数砂轮速度(v)、工作台调定压力(Fa)、进给量(f)对PCD材料的磨除率(Q)和磨耗比(G)影响程度通常用极差、方差分析法来度量.笔者提出了一种性能优越的灰色分析法(即用灰色理论中的灰色关联度和灰色模型)对正交试验结果进行处理.试验证明:进给量参数是影响磨除率和磨耗比的主要因素,工作台调定压力和砂轮速度是次要因素,PCD的刃磨最优工艺方案为f=0.008 mm,Fa=390 N,v=12.6 m/s.通过计算建立了Q和G的灰色模型. 相似文献
16.
Polishing of polycrystalline diamond by the technique of dynamic friction, part 1: Prediction of the interface temperature rise 总被引:1,自引:2,他引:1
Y. Chen L.C. Zhang J.A. Arsecularatne C. Montross 《International Journal of Machine Tools and Manufacture》2006,46(6):580-587
This paper investigates the interface temperature rise in polishing a polycrystalline diamond (PCD) surface. First, the Greenwood–Williamson's statistical asperity model is applied to characterise the surface roughness of a PCD specimen. The result is then used to estimate the contact area and total number of contact asperities under an applied polishing load. The heat generated is taken as the product of the friction force and the relative sliding velocity between the PCD asperities and the metal disk surface. The Jaeger's moving heat source analysis is then applied to determine the fractions of heat flux flowing into the PCD asperities and their counterpart in contact sliding and to give rise to the average temperature rise. A comparison with the observations made in the authors' experiments and those reported in the literature showed that the model predicts very well the temperature rise at the polishing interface. 相似文献
17.
提高煤田采掘用PCD截齿性能的研究 总被引:2,自引:0,他引:2
为了提高煤田采掘截齿的耐磨性与使用寿命,采用金刚石微粉(W40+W20+W5)与粘结剂(Co、Ni等)按一定的比例均匀混合后,与硬质合金基体装入模具,经真空处理后,装入叶蜡石块,在国产六面顶液压机高温高压条件下进行合成,然后用机械、电火花等方法进行加工,研制出金刚石强化柱齿截齿。采用90-94wt%细颗粒金刚石(400目以细)与6-10wt%粘结剂(B、Ti、Si、Co、Ni等)按一定的比例充分混合后,装入特制石墨模具,进行真空处理后,按一定方式组装成叶蜡石合成块,在国产六面顶液压机高温高压条件下进行合成,合成后对其进行球磨,研制出热稳定性金刚石聚晶截齿。切割试验结果表明,其在花岗岩中切割性能可达硬质合金截齿的150倍。预计在硬岩、中硬岩石中使用金刚石强化柱齿截齿、热稳定性金刚石聚晶截齿是最有前途的。 相似文献
18.
Experimental study on ultrasonic elliptical vibration cutting of hardened steel using PCD tools 总被引:1,自引:0,他引:1
Diamond tools cannot usually be applied for machining hardened steels while applying conventional cutting technique. As an alternative, ultrasonic elliptical vibration cutting (UEVC) technique was successfully applied for obtaining mirror surface on such steels using single crystal diamond (SCD) tools. In order to reduce production cost without compromising mirror surface quality, polycrystalline diamond (PCD) tools may be tested against highly expensive SCD tools. However, study on machining of hardened steel using PCD tools applying the UEVC technique has not yet been reported. The current research presents an experimental study on UEVC of hardened stainless steel (a typical Stavax, hardness 49 HRC) using the PCD tools. Face turning experiments were carried out to investigate the effects of three machining parameters: nominal depth of cut, feed rate, and nominal cutting speed on output performances such as cutting force, tool flank wear, surface roughness, and chip formation. Experimental results show that nominal cutting speed has very strong influence on the output performances, compared to the other two parameters. The surface roughness improves with a decrease in cutting speed. A mirror-like surface of approximately 804 mm2 with a roughness value Ra of 11 nm was achieved at a lower cutting speed. Theoretical explanations have been given to support the results drawn from the UEVC experiments. It can be concluded that, while applying the UEVC technique, the inexpensive PCD tools instead of the SCD tools can be effectively applied to obtain optical surface for producing precise molds from the hardened steel. 相似文献
19.
PCD槽刀加工工艺过程的探讨 总被引:1,自引:0,他引:1
本文探讨了用PCD槽刀加工硅铝合金活塞环槽存在的成本较高,及在焊接、刃磨等关键工序上易出现的问题,通过试验可降低刀具成本30~50%。保证刀具精度,尺寸误差在0.005mm范围内,且刃口光滑平直,角度准确,延长了刀具的使用寿命,每把槽刀可加工5000~8000件活塞,受到用户欢迎。 相似文献
20.
Machinability of ultrafine-grained copper using tungsten carbide and polycrystalline diamond tools 总被引:1,自引:0,他引:1
Mason Morehead Yong Huang K. Ted Hartwig 《International Journal of Machine Tools and Manufacture》2007,47(2):286-293
Equal channel angular extrusion (ECAE) is an effective process to produce bulk ultrafine-grained (UFG) materials from regular coarse-grained materials. Such ECAE-processed materials typically excel in strength, wear resistance, ductility, and high strain-rate superplasticity, with promising applications in lightweight transportation and medical industries. Precision machining work is generally indispensable for further applications after bulk materials are produced by ECAE. To effectively and efficiently machine such ECAE-processed materials for further broad applications, machining issues such as machinability and tool material selection should be considered. This study was undertaken to investigate the machinability of ECAE-processed pure copper using both tungsten carbide (WC) and polycrystalline diamond (PCD) cutting tools in order to facilitate broad applications of ECAE-processed UFG coppers. It is found that despite its higher cost, PCD is favored to machine UFG copper based on this study since it has better wear resistance, gives lower cutting forces, yields a better workpiece surface finish, and results in no smearing on the workpiece. In machining UFG copper, depth of cut notching was observed as the wear pattern and abrasion as the wear mechanism for the WC tool, while flank wear was observed as the wear pattern and diffusion as the wear mechanism for the PCD tool. 相似文献