Advances in Abrasive Technology IX

Paper Title Page

Authors: Hiroshi Matsuura, Yasuhiro Kunieda, Nobuhito Yoshihara, Tsunemoto Kuriyagawa
Abstract: A Nd:YAG crystal having a special structure achieved laser operation with an extinction ratio of over 20 dB, a CW (continuous wave) average power of 6 W, a pulse width of 50 ns, and repetition rates in the range 1 kHz – 10 kHz for an output wavelength of 1064 nm for effectively cooling the crystal for the case of laser dressing. The birefringence induced by the stress applied to the crystal results in the production of elliptical polarization before the Brewster-window and thus decreases the laser efficiency. In this paper, we analyzed the relationship between the distortion and the birefringence in a Nd:YAG crystal and the resulting effect on the laser power.
Authors: Nam Hun Kim, Nam Kyung Kim, Eun Sang Lee
Abstract: This paper describes evaluation and monitoring methods of machining characteristics for developed cutting machine of micro grooves. Experiments were conducted under various process conditions such as spindle revolution speed, feed rates and depth of groove. A precision blade was manufactured to cut micro grooves in the mold of a PDP barrier rib, while taking the groove shape into consideration. The groove cutting characteristics of the blade were evaluated by experimenting on STD11 and cemented carbide. AE technology was used to observe the state of the grooves. The obtained AE signals reliably represented the grooving quality and cutting conditions, as demonstrated through the use of a fuzzy C-means algorithm.
Authors: Koichi Okuda, Y. Takeno
Abstract: High accuracy and high efficiency machining of micro parts such as a contact probe for a current inspection of semiconductor is increasingly demanded. In this study, we have focused on a micro cutting technology of a carbon tool steel which is a typical material for a contact probe. In order to put the precision cutting of the high strength material into practice, it is essential to understand the micro cutting phenomenon such as the surface texture, the tool wear with small depth of cut and low cutting speed. Then, the precision cutting experiments of a carbon tool steel (SK105) by titanium carbide and ultra-fine grained tungsten carbide tools were carried out with an ultra-precision cutting machine. It was found that the feed rate, the cutting speed and the edge sharpness of tool significantly influence the surface finish.
Authors: Shin-Ichiro Hira, Masato Yoshioka
Abstract: This report describes fabrication of polytetrafluoroethylene (PTFE) to make up a micro-fluidic device for the application to a Micro-Total Analysis System ( -TAS). This material is chosen as a material of the device because of many excellent properties such as high chemical resistance and high heat resistance in comparison with the other polymers. Mechanical micro-cutting process is employed for the fabrications of the required elemental micro-structures such as a micro-channel and a micro-reservoir for the device. In general, burrs are easily generated in the cutting of soft materials such as PTFE. It is thought to be the most important to find how to prevent the burr generation and how to clean the generated burrs to assure the device quality. Therefore, in order to obtain the fundamental information about the burr generation in the micro-cutting of PTFE, through hole drilling, groove milling and face milling are performed. As a result, the elemental micro-structures without burrs are fabricated on PTFE plate. Furthermore the plate is sealed by sealing film assisted with pressure. By testing leakage with fluid sample, it is confirmed that the pressure-aided sealing is useful.
Authors: Takeshi Akamatsu, Koichi Kitajima, Y. Matsumoto, T. Kiriyama
Abstract: The machining of metal dies involves a variety of processes that include grinding, polishing and electrical discharge machining in addition to various cutting processes such as turning, boring, and milling. The precise machining of complex dies, particularly in deep machining, has largely been done by electrical discharge machining in the past, because the use of end mills and other cutting tools for such work has been difficult. In recent years, however, problems such as low machining efficiency and the creation of an affected layer have made the use of end mill cutting tools the general approach to this task. In the research reported here, our objective was to establish guidelines for the optimum design of small radius ball end mills for the deep machining of dies by systematic investigation of the cutting tool characteristics, which is to say the rotational behavior, cutting resistance, actual rate of depth of cut and machining accuracy of small radius ball end mills. Here, the guidelines obtained for ultra-deep, highly-accurate machining that is applicable to machining programs and is based on quantitative results for amounts of tool wear and tool deflection that obtained using the optimum tool shape reported earlier are presented.
Authors: Toshiyuki Noji, Kazuo Nakamura, Hideyuki Horisawa, Nobuo Yasunaga
Abstract: In order to reduce the thermal influences in laser machining of sapphire surface, effects of a short-pulse ultra-violet laser were investigated. For the UV laser, the Fifth harmonic generation (Fifth HG) wave of an Nd:YAG laser (wavelength:213nm) was utilized. Significant reduction of thermal damages on the surface was demonstrated with the Fifth HG pulses compared to longer wavelengths of the Nd:YAG laser. It was shown that the control of depth of bottom surface with reduced thermal influences was possible in lower fluence cases(less than 40 J/cm2) with a homogenized beam and smooth surface roughness Ra < 200nm was obtainable.
Authors: Zhen Long Wang, Bai Dong Jin, Guo Hui Cao, Z.W. Wei, Wan Sheng Zhao
Abstract: This paper proposes a new deposition method using micro electrical discharge machining (EDM) to deposit micro spiral structure in gas. First, the basic principles of micro electrical discharge deposition (EDD) are analyzed and the realized conditions are predicted. Then with an ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of experiments are carried out on the micro spiral structure deposition in air. The effects of major processing parameters, such as the discharge current, discharge duration, pulse interval, gravity and working medium, are obtained. As a result, a 19-circle micro spiral structure with 0.19mm in external diameter, 0.1mm in wire diameter and 3.39mm in height is deposited. Measurements show that the deposited material has obvious delaminating structure, the components of which depend on those of the tool electrode material, although Zn in the electrode is oxidized to ZnO. This method establishes the research basis for micro three-dimensional deposition machining.
Authors: P. Wei, Yu Zhu, Q.F. Tan, G.H. Duan, G.H. Gao
Abstract: In order to improve the radial superresolution of the two-photon microfabrication, the superresolution diffraction theory was introduced in detail. The theoretical analysis of the photosensitive resist based on the exciting power and concentration of free radical was given.. And the superresolution diffractive optical element was applied in the two-photon microfabrication system. Simulation results indicated that the radial superresolution of the two-photon microfabrication can be improved with the superresolution diffractive optical element.
Authors: Li Ding Wang, Jun Sheng Liang, C. Liu, Gong Quan Sun
Abstract: As one part of the efforts to break the bottleneck of power sources in development of integrated micro systems, a silicon based air-breathing micro direct methanol fuel cell (μDMFC) was developed in this work. By using micro-machining technologies compatible with that in processing of the other MEMS devices, the anode and cathode micro flow-field plates had been successfully fabricated on a pair of 2-inch silicon wafers. The silicon μDMFC was evaluated under ambient conditions using aqueous methanol solution with different concentrations. Results show that open circuit potential (OCP) of the μDMFC was above to 0.6 V, and by using 3mol/L methanol, the peak current density and power density of the silicon μDMFC could reach 28mA/cm2 and 8mW/cm2, respectively.
Authors: Li Da Shen, Y.H. Huang, Zong Jun Tian, Guo Ran Hua
Abstract: Nanostructured ceramic bulk materials were achieved from nano-Al2O3 ceramic powders via direct selective laser sintering (SLS). SLS as a non-traditional machining technology of Rapid Prototyping was introduced and compared with other ceramic forming technologies. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to analyze the microstructure of the ceramic bulk materials. These results demonstrated that the nano-Al2O3 ceramic powders can be sintered into bulk materials maintained nanostructure with some technological parameters. It was found that the nanostructured ceramic bulk exhibited unique microstructure and was free formed rapidly by this sintering technology.

Showing 91 to 100 of 129 Paper Titles