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金刚石刀具高速精密切削加工的研究 总被引:7,自引:4,他引:7
采用聚晶金刚石刀具和天然金刚石刀具对LY12高强度铝合金进行了高速精密切削试验 ,系统研究了切削条件、切削用量对加工表面粗糙度的影响规律。结果表明 ,在比常用切削速度高 8倍的高速切削速度范围内(v=80 0~ 12 0 0m/min) ,采用圆弧刃天然金刚石刀具可获得Ra0 0 4~ 0 0 6 μm的高光洁加工表面 ;采用直线刃聚晶金刚石刀具可获得Ra0 0 7~ 0 1μm的光洁加工表面。切削速度对加工表面粗糙度的影响主要受到机床动态特性的制约 ;进给量的选择范围较大 ;背吃刀量对加工表面质量影响极大 ,为获得较小表面粗糙度必须合理选用背吃刀量 相似文献
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张小行 《世界制造技术与装备市场》1999,(3):J012-J013
1月12日在Aalen举办的一次家庭集会上,精密刀具制造集团展示了Mapal精密刀具,Dr.Kress合资公司为满足今后几年的要求已作了很好的准备。该企业因其车螺纹铰刀而为专业人员所熟悉。50年前建立的家庭企业随着时间的推移已经发展成为一个企业集团。该集团除钻孔工具外还优先提供汽车工业用的夹具、调整仪和精密加工刀具。 相似文献
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超精密切削氟化钙单晶金刚石刀具磨损研究 总被引:1,自引:0,他引:1
为了研究氟化钙(CaF2)单晶超精密切削过程中的金刚石刀具磨损及其对切削过程的影响,对CaF2晶体进行了超精密切削实验,系统观测了刀具磨损形貌随切削路程的变化趋势,分析了刀具磨损机理,同时通过分析不同切削路程下切削表面微观形貌和切削力的变化,对刀具磨损与切削模式之间的关系进行了探讨。研究表明,超精密切削CaF2晶体时刀具磨损模式为沟槽磨损和缺口破损,刀具磨损随切削路程的演变过程为后刀面沟槽磨损扩展到前刀面缺口破损,同时相应的切削模式由延性去除转变为脆性去除。该研究结果为大口径CaF2晶体纳米尺度延性域切削提供了技术支持。 相似文献
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本文对天然单晶金刚石刀具的刃口组织结构、强度及其磨损进行了分析和试验。指出定量解决金刚石刀具耐磨性技术是当今最迫切的研究方向。 相似文献
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随着航空、航天、船舶等工程领域对具有薄壁结构的钛合金零件需求的不断提高,加工效率相对较高且适用于曲面等复杂几何形状制造的微铣削加工方法在钛合金薄壁加工中获得了广泛的应用。然而由于其刚度较低,在微铣削加工钛合金薄壁时极易产生工件变形、失稳和振动等问题,并导致加工精度的下降。为此从理论建模、有限元仿真和试验测量三个方面分析了国内外弱刚度金属薄壁微铣削技术研究的现状。相关研究表明,在加工过程中对薄壁变形进行准确预测对于薄壁微铣削加工误差补偿模型的建立与薄壁加工精度的提高具有重要意义。并指出,在获得数学规律的基础上对薄壁微铣削加工变形和该变形对加工精度造成的影响之间蕴含的物理关系仍有待进一步的研究。 相似文献
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A fast-tool servo-machining process is typically utilized to generate sinusoidal microstructures for optical components only when the clearance angle of the cutting tool is greater than the critical value. This paper focuses on the generation characteristics of microstructures for surface texturing applications when the clearance angle of the cutting tool is smaller than this critical angle. A method for calculating the microstructure profile amplitude and wavelength is introduced for the prediction of microstructure generation. Cutting tests were conducted, and the measured results were quite close to the corresponding calculated results, further verifying the capability of the proposed analytical model. 相似文献
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Fracture and drop-off of diamond grains are thought to be suppressed if the diamond grains used, such as those for electroplated wires, are coated with a material having a higher coefficient of thermal expansion than diamond and having good adhesion to the binder metal. In this study, we selected titanium carbide and titanium carbonitride as materials with such characteristics, and investigated their coating methods. The titanium carbide coating was formed by heating a mixture of diamond plate or diamond grains and titanium powder in vacuum at a temperature lower than the melting point of titanium. Titanium carbonitride formation tests were performed in two ways: by forming a titanium carbide coating and titanium carbonitride in the same chamber continuously or by exposing the sample to the atmosphere after titanium carbide formation and subsequently reheating it in nitrogen. The titanium carbide coating was tested by heating the mixture of the diamond plate and the titanium grains in vacuum of 2.0 × 10−3 Pa or less at 1073–1273 K for 60–120 min. For the titanium carbonitride coating, the primary titanium carbide coating was applied at temperatures of 1123–1273 K for 60 min. Then the titanium carbonitride formation was done at the same temperature but with different heating times. Products on the diamond after heating tests were analyzed using X-ray diffraction. Results show that titanium carbide can be coated onto the diamond surface by heating the mixture of diamond and titanium powder in vacuum at 1073 K or at a higher temperature. Results demonstrated further that titanium carbonitride can be formed by heating the diamond plate or the diamond grains coated with titanium carbide in nitrogen at a temperature higher than 1123 K. The titanium carbide layer thickness and the ratio of nitrogen in the titanium carbonitride increased concomitantly with increased heating temperature and increased heating time. 相似文献
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Nickel alloys possess the excellent potential at high temperature and resistance to oxidation/corrosion owing to its high nickel content. These materials necessitate non-traditional machining methods. The rotary ultrasonic machining (RUM) process comes into existence as a superior alternative to the conventional machining of nickel alloys. The processing of these alloys using RUM needs attention. This article details the multi-response optimization in RUM of nickel alloy using the desirability concept. The present work is carried out with two shapes of the tool: (i) Plain tool and (ii) lateral slotted tool. During RUM, the process parameters—power rating tool rotation, abrasive diamond grit size and feed rate are varied. Compared with the plain tool, the lateral slotted tool shows the more efficient machining rate (MR) with less tool wear (TW). The micro-graphs disclose the mechanism of MR and TW during RUM. 相似文献
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Haibo LIU Chengxin WANG Te LI Qile BO Kuo LIU Yongqing WANG 《Frontiers of Mechanical Engineering》2022,17(4):55
During the overall processing of thin-walled parts (TWPs), the guaranteed capability of the machining process and quality is determined by fixtures. Therefore, reliable fixtures suitable for the structure and machining process of TWP are essential. In this review, the key role of fixtures in the manufacturing system is initially discussed. The main problems in machining and workholding due to the characteristics of TWP are then analyzed in detail. Afterward, the definition of TWP fixtures is reinterpreted from narrow and broad perspectives. Fixture functions corresponding to the issues of machining and workholding are then clearly stated. Fixture categories are classified systematically according to previous research achievements, and the operation mode, functional characteristics, and structure of each fixture are comprehensively described. The function and execution mode of TWP fixtures are then systematically summarized and analyzed, and the functions of various TWP fixtures are evaluated. Some directions for future research on TWP fixtures technology are also proposed. The main purpose of this review is to provide some reference and guidance for scholars to examine TWP fixtures. 相似文献
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We conducted a series of screening experiments to survey the influence of machining parameters on tool wear during ductile regime diamond turning of large single-crystal silicon optics. The machining parameters under investigation were depth-of-cut, feed rate, surface cutting speed, tool radius, tool rake angle and side rake angle, and cutting fluid. Using an experimental design technique, we selected twenty-two screening experiments. For each experiment we measured tool wear by tracing the tool edge with an air bearing linear variable differential transformer before and after cutting and recording the amount of tool edge recession. Using statistical tools, we determined the significance of each cutting parameter within the parameter space investigated. We found that track length, chip size, tool rake angle and surface cutting speed significantly affect tool wear, while cutting fluid and side rake angle do not significantly affect tool wear within the ranges tested. The track length, or machining distance, is the single most influential characteristic that causes tool wear. For a fixed part area, a decrease in track length corresponds to an increase in feed rate. Less tool wear occurred on experiments with negative rake angle tools, larger chip sizes and higher surface velocities. The next step in this research is to perform more experiments in this region to develop a predictive model that can be used to select cutting parameters that minimize tool wear. 相似文献
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High pressure high temperature (HPHT) synthetic diamond is rapidly replacing natural diamond in precision machining industry due to its consistency in quality and cost. It is believed by some manufacturers that HPHT diamond cutting tool is virtually free of impurities, inclusions and cracks. This paper is to analyze defects inside HPHT diamond crystal by density test, optical microscopy, SEM, Raman, and XRD. Results show that HPHT diamond is relatively clean, with less chemical elements inside in comparison with natural diamond. However, there are cracks, pit holes, and bubbles in/on the crystal, some tracing amount of cementite (Fe3C), γ-Fe, and nickel based carbides also exist in the HPHT diamond crystal, causing less accurate cutting tool edge and surface integrity. Residual stresses in HPHT diamond are compressive but high in value, may lead to cutting tool brittleness and micro-chipping, which is a common reason for diamond tool failing in precision machining. 相似文献
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为了提高聚晶金刚石(PCD)刀具的生产效率,改进加工表面质量并减少刃磨余量,利用慢走丝电火花线切割机床(WEDM)对PCD复合片进行了加工工艺试验.对PCD复合片进行了5次切割,并分别测量了每次加工后的表面粗糙度、富钴界面层凹槽深度及宽度和PCD层刃口加工质量.试验结果表明:PCD复合片经慢走丝线切割多次加工,能够得到较好的表面质量,在众多影响因素中金刚石颗粒大小对加工质量影响较大;其中CTH025型号和CTB010型号的最终表面粗糙度分别为Ra=0.85 μm和Ra=0.57 μm,富钴界面层凹槽的深度分别为16.3 μm和5.7 μm,刃口处切口缺陷的尺寸也与金刚石颗粒的尺寸相当.经WEDM加工后的PCD复合片的刃磨余量可控制在4~15 μm左右. 相似文献