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Key engineering materials
Trans Tech Publications Ltd.
Key engineering materials

Trans Tech Publications Ltd.

半月刊

1013-9826

Key engineering materials/Journal Key engineering materials
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    On-machine Heat Treatment System Using YAG Laser: Laser Hardening of Micro-cutting Edge

    Keiji OGAWAHeisaburo NAKAGAWAAkira OHTSUKA
    P.203-207页
    查看更多>>摘要：This paper describes the laser hardening of micro-cutting edges using an on-machine heat treatment system with a YAG laser. Various laser conditions were evaluated to perform laser quenching on a machine tool without melting at the edges. We also investigated the influence of the motion accuracy of the machining center on the quenching characteristic of micro-cutting edges after laser irradiation. We clarified that we could quench both the straight and curved corner parts by arranging proper laser irradiation conditions considering the motion accuracy of the machining center.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Fabrication of Ultraprecision Millimeter-thick Elliptical Neutron Focusing Mirror Substrate by Local Wet Etching

    Fumiya YamagaMikinori NaganoNobuyuki ZettsuDai Yamazaki...
    P.208-212页
    查看更多>>摘要：Numerically controlled local wet etching (NC-LWE) is a novel technique to fabricate the ultraprecision optical components and/or finishing the functional materials. In this technique, a figuring is performed by controlling the dwelling time of the combination nozzle, which consists of a supply and a suction part of an etchant, on the workpiece. In this paper, we proposed fabrication process of millimeter-thick elliptical neutron focusing mirror substrate by applying NC-LWE figuring involving CeO_2 slurry polishing. We fabricated a millimeter-thick elliptical neutron focusing mirror substrate with a figure error of less than 0.2 μm and obtained a surface roughness of less than 0.15 nm rms.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Fabrication of Damage-free Curved Silicon Crystal Substrate for a Focusing X-ray Spectrometer by Plasma Chemical Vaporization Machining

    Mao HosodaKazuaki UedaMikinori NaganoNobuyuki Zettsu...
    P.213-217页
    查看更多>>摘要：In the X-ray fluorescence analysis on sub-micron particle, application of the doubly curved crystal (DCC) spectrometer with Johansson-type geometry is effective to improve the lowest limit of detection because DCC makes it possible to focus and monochromatize an X-ray beam simultaneously. A strain-free crystal is essential for the high-performance focusing crystal spectrometer. We propose the application of the open-air type numerically controlled plasma chemical vaporization machining (NC-PCVM), which utilizes neutral reactive species generated by atmospheric pressure plasma, to fabricate the DCC substrate. By applying NC-PCVM technique, a curvature radius error of 0.08% was obtained, and there was no degradation of the crystallinity of the Si (111) substrate.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Effect of Substrate Heating in Thickness Correction of Quartz Crystal Wafer by Plasma Chemical Vaporization Machining

    Masaki UedaMasafumi ShibaharaNobuyuki ZettsuKazuya Yamamura...
    P.218-222页
    查看更多>>摘要：Quartz resonator is a very important device to generate a clock frequency for information and telecommunication system. Improvement of the productivity of the quartz resonator is always required because huge amounts of resonator are demanded to install to various electronic devices. Resonance frequency of the quartz resonator is determined by the thickness of the quartz crystal wafer. Therefore it is essential to uniform the thickness distribution of the quartz crystal wafer with nanometric level. We propose the improvement process of the thickness distribution of the quartz crystal wafer by numerically controlled correction using atmospheric pressure plasma which is noncontact and chemical removal technique. We have already succeeded in obtaining a thickness uniformity of 33.1 nm within 2 min in the thickness correction of an AT-cut quartz crystal wafer with an area of 24 mm × 24 mm. However, increase of removal rate and improvement of correction accuracy are required for industrial manufacturing. Heating effects of the quartz crystal wafer in the removal rate and the correction accuracy were investigated. The heating of the substrate and compensate of the scanning speed of the worktable in accordance with the variation of the surface temperature enabled an increase of 50% in removal rate and 10-nanometric-level accuracy in correction of the thickness distribution of the quartz crystal wafer.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Research on Ultrasonic Vibration Combined with Grinding Machining and its Application in Processing Brittle Hard Materials

    Yongjun ZhangYongjun TangXiaokang Liu
    P.223-227页
    查看更多>>摘要：A system of ultrasonic combined with grinding has been designed, and one novel connective method of straight screw combined with taper surface has been applied in spindle, so compact size and high revolving accuracy can be achieved. Modal analysis of ultrasonic vibration system has been implemented by FEM (Finite Element Method), and its optimal dimension has been calculated to find out optimal vibration estate. Full-bridge converter has been applied in driving circuit of ultrasonic vibrator, and auto-frequency tracking has been designed in order that ultrasonic vibration works on resonant or quasi-resonant frequency. Finally, machining experiments have been fulfilled about ultrasonic combined with grinding, and its machining effect has been distinctly improved comparing ordinary grinding machining.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Study on Machining of Cracking Notches for Automotive Connecting Rod Using WEDM

    Yongjun TangYuanbo LiYongjun ZhangChunqiang Zhou...
    P.228-232页
    查看更多>>摘要：In order to resolve the problem of connecting rod notches machining, a new process of WEDM (Wire Electric Discharge Machine) has been presented, and it is greatly possible that expensive laser process can be replaced by WEDM in virtue of its unique advantages. Firstly, process parameters of notch have been analyzed, and project of machining notch using WEDM has been introduced, including measures to achieve good-quality notch. The relationship between cutting speed and power supply parameters has been investigated, and it is discovered that micro-crackle on bottom of notch are greatly effect to fracture splitting process, also new idea of active controlling micro-crackle has been presented. Finally, fracture splitting machining has been carried out. The cost and entrance standard of fracture splitting process are greatly dropped owing to new breakthrough of machining notch using WEDM.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Micro-EDM for an Aluminium Matrix Composite

    Fuqiang HuB.Y.SongJ.C.BaiP.J.Hou...
    P.233-237页
    查看更多>>摘要：The silicon carbide particle reinforced aluminium matrix composite (SiCp/Al) which is acknowledged as one of the most competitive metal matrix composites is now widely applied in aviation, aerospace and military fields, and its application is extending gradually. As a result of the hard and brittle SiC particles contained, mechanical machining of the material is difficult, but the method of electric discharge machining (EDM) has certain prominent advantages. In this paper, SiCp/Al was machined using micro-EDM. First, a Φ40μm × 4.1mm micro tool electrode of which the aspect ratio is up to 100 was made; and then, through experiment, the impact of open-circuit voltage and electrode material on processing speed and electrode wear was analyzed; finally, 28μm wide micro slits, micro square platform of 34μm long on each side and other micro three-dimensional structure were machined. Research and experimental results show that the use of appropriate micro-machining parameters and reasonable processing methods can improve processing performance to better achieve the micro-EDM of SiCp /Al.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Electrical Discharge Machining of Submicron-Diameter Micropins

    Hiromitsu UenoYuki KonoKai Egashira
    P.238-241页
    查看更多>>摘要：The wire electrodischarge grinding (WEDG), which is one of the electrical discharge machining (EDM) methods, of submicron-diameter zinc micropins was attempted using a relaxation-type pulse generator. Tungsten wire of 30 urn diameter was employed as the tool electrode. The open-circuit voltage was set at lower than or equal to 15 V in the finish machining step. The electrostatic capacitance of the pulse generator was its stray capacitance only. As a result, a micropin of 0.3 urn diameter was processed. They are the smallest-diameter micropins fabricated by EDM, to the best of our knowledge.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    The Function Deployment of EDM Machine Tools

    Rui XueChangNing GuoXiaoXin YangJingYu Pei...
    P.242-246页
    查看更多>>摘要：This paper addresses the further developing and utilizing about the functions of EDM machine tool on the basis of researching the numerical controls of EDM machine tool itself. Experiments of testing critical gap distances, single pulse discharges and single pulse discharge gap distances have been performed by the machine tool without any extra help of auxiliary instruments or equipments. The measuring accuracy and repeated testing accuracy is the numerically controlled displacement precision of the machine tool itself. The development of this function would have a great impact on enlarging the utilizations of EDM machine tools, on evaluating the behavior of EDM effectively and on designing the jumping displacement of electrodes reasonably.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd

    Practical Design for Energy-Saving EDM Supply System

    Wang YukuiWang ZhenlongSong BoyanHu Fuqiang...
    P.247-252页
    查看更多>>摘要：In this paper a kind of architecture for an energy-saving EDM supply composed of three serial stages in the topology and its practical design are discussed. Various special controllers and its assisted circuits are introduced in the each of the three serial stages. The PFC controller UC3854 placed on the front stage provides satisfactory input power factor of the system. The PWM controller UC3875 mounted on the middle stage realize the closed control of the current of the inductance limiting machining current. An embedded controller PIC 16F877 on the final stage is chosen to setting such machining variables as peak current, discharge duration and pulse interval. The communication with host PC is also realized by the same embedded controller. The architecture based on model of multi-controller parallel working guarantees capacity of the system real-time process. The prototype of the energy-saving EDM pulse supply using MOSFET power device is developed. A lot of experiments have demonstrated the feasibility and stability of the practical design.
      原文链接:
    • NETL
    • NSTL
    • Trans Tech Publications Ltd