共查询到20条相似文献,搜索用时 15 毫秒
1.
Jianguo Zhang Norikazu Suzuki Yilong Wang Eiji Shamoto 《Journal of Materials Processing Technology》2014,214(11):2644-2659
This paper presents essential investigations on the feasibility of ductile mode machining of sintered tungsten carbide assisted by ultrasonic elliptical vibration cutting technology. It lays out the foundations toward efficient application of elliptical vibration cutting technology on tungsten carbide. Tungsten carbide is a crucial material for glass molding in the optics manufacturing industry. Its grain size and binder material have significant influence not only on the mechanical and chemical properties but also on the machining performance of tungsten carbide. In order to investigate the influence of material composition on tungsten carbide machining, a series of grooving and planing experiments were conducted utilizing single crystal diamond tools. The experimental results indicated that as compared to ordinary cutting where finished surface deteriorates seriously, ductile mode machining can be attained successfully by applying the elliptical vibration cutting technique. It was also clarified that the binder material, the grain size, cutting/vibration conditions as well as crystal orientation of the diamond tool have significant influence on the tool life and the machined surface quality. Based on these fundamental results, feasibility of micro/nano-scale fabrication on tungsten carbide is investigated. By applying amplitude control sculpturing method, where depth of cut is arbitrary changed by controlling the vibration amplitude while machining, ultra-precision textured grooves and a dimple pattern were successfully sculptured on tungsten carbide in ductile mode. 相似文献
2.
Development of Ultrasonic Vibration Assisted Polishing Machine for Micro Aspheric Die and Mold 总被引:3,自引:0,他引:3
Demands are increasing for micro axis-symmetric aspherical lenses to be installed in various optical devices. The micro glass lenses are generally molded by glass press process with micro aspheric ceramic molding dies or molds made of tungsten carbide or silicon carbide. These dies and molds are mostly ground with micro diamond wheels, but require additional finishing process as the size of the dies and molds become smaller and the required accuracy becomes higher. In order to finish micro aspheric dies and molds with diameter less than 3mm, an ultrasonic vibration assisted polishing machine is developed. A small polishing tool is mounted on a 3-axis controlled table, and vibrated at an ultrasonic frequency with piezo-electric actuators. The polishing pressure can be controlled with a resolution of 2 mN. Some micro aspheric molding dies made of binder-less tungsten carbide were polished, and the form accuracy below 70 nmP-V and surface roughness of 7 nmRy were obtained with the developed machine. 相似文献
3.
Development of a Elliptical Vibration Milling Machine 总被引:1,自引:0,他引:1
A unique elliptical vibration milling machine is developed by utilizing a double-spindle mechanism. The developed machine generates circular vibratory motion of the cutting tool mechanically by rotating an eccentric sleeve with a built-in motor. The radius and the maximum frequency of the circular vibration are set to 0.5 mm and 167 Hz respectively. The developed machine is applied to elliptical vibration planing by clamping the tool spindle, and also to elliptical vibration end milling by rotating the inner tool spindle as well at the same time. The machining tests of hardened steel with CBN and coated carbide tools are carried out, and it was proved that the elliptical vibration cutting shows better results as compared with conventional cutting without elliptical vibration motion. A mirror surface on hardened steel with a roughness of about 0.11 μm Ra was obtained by elliptical vibration planing by employing a single crystal diamond tool. 相似文献
4.
Simple analytical models of three dimensional (3D) elliptical vibration cutting are developed in order to simulate the cutting process quickly and to understand the basic mechanics. The elliptical vibration cutting has recently been applied in industry mainly to ultraprecision machining of dies and molds, where the vibration locus is not generally perpendicular to the cutting edge and thus all directions of shear, chip flow and cutting force have the 3D components. Therefore, the 3D elliptical vibration cutting models are developed, and the basic cutting mechanics are discussed in the present research. 相似文献
5.
6.
Development of micro milling tool made of single crystalline diamond for ceramic cutting 总被引:1,自引:0,他引:1
In order to machine micro aspheric ceramic molds precisely and efficiently, micro milling tools made of single crystalline diamond (SCD) are developed. Many cutting edges are fabricated 3-dimensionally on the edge of a cylindrical SCD by a laser beam. Flat binderless tungsten carbide mold was cut with the developed tool to evaluate the tool wear rate and its life. Some micro aspheric molds of tungsten carbide were cut with the tool at a rotational speed of 50,000 min−1. The molds were cut in the ductile mode. The form accuracy obtained was about 100 nm P–V and the surface roughness 12 nm Rz. 相似文献
7.
Effect of machining parameters and coating on wear mechanisms in dry drilling of aluminium alloys 总被引:1,自引:1,他引:1
M. Nouari G. List F. Girot D. Ghin 《International Journal of Machine Tools and Manufacture》2005,45(12-13):1436-1442
The temperature generated by friction and plastic deformation in the secondary shear zone strongly controls tool wear. At lower cutting speeds tool wear is not severe insofar as the temperature is not significant. When the cutting speed is increased, there is a transition in wear mechanisms from abrasion and/or adhesion to diffusion. In the present paper, the change in wear mechanisms as a function of cutting speed and coating material is discussed. The cutting tests were performed on a rigid instrumented drilling bench without the use of cutting fluids. AA2024 aluminium alloy was used to investigate the wear mechanisms of cemented tungsten carbide and HSS tools. Three cutting speeds (25, 65 and 165 m/min) and a constant feed rate of 0.04 mm/rev were selected for the experiments. The best results in terms of maximum and minimum hole diameter deviations and surface roughness are obtained for the uncoated and coated tungsten carbide drills. The results also show that HSS tool is not suitable for dry machining of AA2024 aluminium alloy. 相似文献
8.
9.
Needs of micro structured components and its molds/dies are increasing in a solar cell system, an infrared night view and micro medical devices. In order to improve the accuracy of the structured molds/dies made of tungsten carbide, a new truing method of the diamond grinding wheel by alloy metals was proposed and the performance of the proposed truing method was evaluated. In the grinding test, Fresnel molds of tungsten carbide were ground by using the diamond wheel trued with the alloy metal. From the experiments it was clear that the form accuracy and surface roughness of the ground molds were improved. 相似文献
10.
Chandra Nath Mustafizur Rahman Ken Soon Neo 《International Journal of Machine Tools and Manufacture》2009,49(14):1089-1095
Sintered tungsten carbide (WC) is an extremely hard and brittle material extensively used in tool manufacturing industries. However, the current cutting technologies for shaping this typical hard-to-machine material are still cost ineffective. In this study, polycrystalline diamond (PCD) tools are used to study the machinability of sintered WC (~15% Co) by applying the ultrasonic elliptical vibration cutting (UEVC) technique. Firstly, it presents the UEVC principle and the effects of speed ratio (i.e. the ratio of the nominal cutting speed to the maximum tool vibration speed in the cutting direction) on the tool–workpiece relative motion as the cutting speed greatly influences the UEVC performance. Then UEVC experiments are carried out to analyze the cutting force, tool-wear progression, chip formation and surface quality against the cutting time at different speed ratios. The results show that when the speed ratio decreases, the resultant cutting force and the tool flank wear decrease while the surface finish improves. Average surface roughness, Ra, in a range between 0.030 and 0.050 μm is achieved at speed ratios less than 0.107. The experimental findings suggest that the commercial PCD tools can be used to machine sintered WC to achieve ultraprecision surface by applying the UEVC technique, which will be cost effective for miniature cutting technologies in future. 相似文献
11.
A study on the effect of tool nose radius in ultrasonic elliptical vibration cutting of tungsten carbide 总被引:1,自引:0,他引:1
Chandra Nath Mustafizur Rahman Ken Soon Neo 《Journal of Materials Processing Technology》2009,209(17):5830-5836
Nowadays, ultrasonic elliptical vibration cutting (UEVC) technique is being successfully applied for ultraprecision machining of difficult-to-cut materials. Previous study reported that the tool geometry especially tool nose radius notably influences the performance of 1D ultrasonic vibration cutting (UVC). However, the effect of tool nose radius in the UEVC technique is yet to be studied. This study aims to investigate the effects of tool nose radius on the UEVC performance in terms of cutting force, tool wear and surface finish when machining a hard-to-cut material, sintered tungsten carbide (WC), using PCD tools. The experimental results show that the UEVC technique performs remarkably better in all aspects at a 0.6 mm nose radius compared to a lower (e.g. 0.2 or 0.4 mm) and a higher nose radius (e.g. 0.8 mm). When machining about 412 mm2 surface area, an average surface roughness, Ra of 0.010 μm is achieved with a 0.6 mm nose radius. Analyses are conducted to justify the findings in this study. 相似文献
12.
Saeed Zare Chavoshi 《Production Engineering》2011,5(1):37-47
Flank wear occurs on the relief face of the tool and the life of a tool used in a machining process depends upon the amount
of flank wear; so predicting of flank wear is an important requirement for higher productivity and product quality. In the
present work, the effects of feed, depth of cut and cutting speed on flank wear of tungsten carbide and polycrystalline diamond
(PCD) inserts in CNC turning of 7075 AL alloy with 10 wt% SiC composite are studied; also artificial neural network (ANN)
and co-active neuro fuzzy inference system (CANFIS) are used to predict the flank wear of tungsten carbide and PCD inserts.
The feed, depth of cut and cutting speed are selected as the input variables and artificial neural network and co-active neuro
fuzzy inference system model are designed with two output variables. The comparison between the results of the presented models
shows that the artificial neural network with the average relative prediction error of 1.03% for flank wear values of tungsten
carbide inserts and 1.7% for flank wear values of PCD inserts is more accurate and can be utilized effectively for the prediction
of flank wear in CNC turning of 7075 AL alloy SiC composite. It is also found that the tungsten carbide insert flank wear
can be predicted with less error than PCD flank wear insert using ANN. With Regard to the effect of the cutting parameters
on the flank wear, it is found that the increase of the feed, depth of cut and cutting speed increases the flank wear. Also
the feed and depth of cut are the most effective parameters on the flank wear and the cutting speed has lesser effect. 相似文献
13.
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
14.
Micro-glass lenses for digital cameras and blue laser DVD pick-up devices are generally molded by using micro-aspheric ceramic molds made of tungsten carbides. These molds are finished by micro-polishing using loose abrasives after grinding. Improvement to the accuracy of the molds is necessary, and high numerical aperture (NA) optics with steep angles are required. In order to finish the molds of high NA, an ultrasonic two-axis vibration assisted polishing machine with piezo-electric actuators was proposed and developed. Some micro-aspheric molds made of binderless tungsten carbide were polished, and surface roughness of 8 nm Rz was obtained. 相似文献
15.
Ti6Al4V是典型的难加工材料,切削效率低、刀具磨损严重严重,因此提高Ti6Al4V的加工效率和刀具寿命是急需解决的问题。作者对硬质合金刀具加工Ti6Al4V的切削力和磨损特性进行了实验研究。对三种不同刀具在干切削状态下车削Ti6Al4V切削力进行了试验,分析了切削力与切削速度、切削路程的关系,同时讨论了主偏角对TC4车削稳定性的影响。最后,对刀具的的磨损形态和磨损机理进行了研究。粘结、扩散、氧化是硬质合金刀具的主要磨损机理。 相似文献
16.
Oxygen-shielded ultrasonic vibration cutting to suppress the chemical wear of diamond tools 总被引:1,自引:0,他引:1
Ultrasonic vibration has been applied to reduce intense chemical tool wear in ultra-precision diamond cutting of steel and other alloys since a few decades ago. But still, its tool wear suppression mechanisms have not been fully understood. In this paper, the effect of oxygen in suppression of diamond tool wear for ultrasonic vibration cutting is investigated. Experimental results show that the wearing rate is reduced by applying oxygen shielding to the cutting zone in comparison with air and argon. Scientific explanations are also provided for the observed phenomenon through low-pressure metal oxidation experiments and X-ray photoelectron spectroscopy surface analyses. 相似文献
17.
Study of machining accuracy in ultrasonic elliptical vibration cutting 总被引:10,自引:2,他引:10
Chunxiang Ma E. Shamoto T. Moriwaki Lijiang Wang 《International Journal of Machine Tools and Manufacture》2004,44(12-13):1305-1310
The cutting speeds of the tool, the rake angle and clearance angle through the cycles of elliptical vibration cutting for separating type ultrasonic elliptical vibration cutting are defined initially in the present paper. Subsequently, a theoretical model of the thrust cutting force in ultrasonic elliptical vibration cutting is proposed, and the reason of the machining accuracy improvement by applying ultrasonic elliptical vibration is clarified theoretically. Finally, the effect of ultrasonic elliptical vibration cutting on machining accuracy is verified experimentally by utilizing an ultrasonic elliptical vibration cutting system. 相似文献
18.
K.S. Neo M. Rahman X.P. Li H.H. Khoo M. Sawa Y. Maeda 《Journal of Materials Processing Technology》2003,140(1-3):326-331
Ultra-precision machining is one of the most important machining technologies for the manufacture of precision dies and molds. Typically, single point diamond cutting tools are used to machine molds which are coated with electroless nickel (NiP) for such applications. The high cost of diamond cutters and electroless nickel plating, coupled with problems of pre-mature failure of the coating in service and long lead time are negative factors in this approach. Hence, there is a strong need for the direct ultra-precision machining of mold steel and to develop relevant technologies to address the problem of tool wear. In the machining of alloy steel, cubic boron nitride (CBN) has long been used as an ideal cutting tool material but recently binderless CBN or pure CBN (PCBN) with superior mechanical properties has been developed by Sumitomo Electric Industries in Japan. The objective of this paper is to explore the feasibility of using PCBN tools for direct ultra-precision machining of Stavax, a type of alloy steel from ASSAB. The performance characteristics in terms of surface roughness and tool wear of PCBN (Sumitomo IZ900) and conventional CBN (Sumitomo BN600) under different machining conditions were studied and their results were compared. Based on the experimental results, PCBN has been found to perform better in terms of wear resistance compared to conventional CBN tool. It is also able to achieve near mirror finish of less than 30 nm Ra, and hence it appears to be a promising tool for direct cutting of die and mold materials. 相似文献
19.
Development of ultra-precision machining system with unique wire EDM tool fabrication system for micro/nano-machining 总被引:1,自引:0,他引:1
Aiming at quality machining of very hard materials with nanometer level surface quality and 0.1 μm dimensional accuracy, an ultra-precision machining system has been developed. The machine has feed axes accompanied by the counter motion mechanism driven at the center of gravity to eliminate the vibration caused by high acceleration/deceleration. A custom tool fabrication system consists of a 6-axis wire EDM machine and dedicated custom tool CAM system. High quality machining of sophisticated three-dimensional (3D) products made of tungsten carbide has successfully been demonstrated on the developed machine tool with custom-made PCD cutters fabricated by the tool fabrication system. 相似文献
20.
Ultrasonic elliptical vibration transducer driven by single actuator and its application in precision cutting 总被引:3,自引:0,他引:3
The ultrasonic elliptical vibration cutting has been successfully applied to precision cutting due to its superior performances, such as low cutting force, high quality surface finish and long tool life. This paper presented an asymmetrical structural model of the ultrasonic elliptical vibration transducer with only the longitudinal excitation. Based on the modal and static analysis with finite element method, various parameters of the model were modified to meet the needs of the vibration modality and the inherent frequency. A cutting system of the ultrasonic elliptical vibration driven by single longitudinal actuator was developed and the effect of the transducer amplitude and cutting depth on the cutting force was studied in detail. A part with surface roughness of Ra 0.08 μm was achieved. The results showed that the ultrasonic elliptical vibration transducer can be designed rationally with finite element method and single driven ultrasonic elliptical vibration machining can be used in precision cutting. 相似文献