• Title/Summary/Keyword: ceramic tool

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Design and FEM Analysis of Multilayer Piezoelectric Transformer for AC-adapter (AC-adapter를 위한 적층형 압전트랜스포머의 설계 및 유한요소해석)

  • 정현호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.04a
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    • pp.529-533
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    • 2000
  • This paper present a new sort of multilayer piezoelectric ceramic transformer for AC-adapt. This piezoelectric transformer operates n the second thickness extensional vibration mode. The output voltage of the multilayer piezoelectric transformer was simulated using ANSYS. As results, the maximum stress appeared at the two points where one is the middle of input and the other is middle of output side in Second thickness extensional vibration mode. And output voltage was inversely decreased by increasing number of output layers.

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Surface Properties and Tool Wear of Si3n4-hBN Machinable Ceramics in Endmill Machining using Tungsten Carbide Tool (텅스텐 카바이드 공구를 사용한 앤드밀 가공에서 Si3n4-hBN 머시너블 세라믹스의 표면특성과 공구마멸)

  • Jang, Sung-Min;Cho, Myeong-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.1
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    • pp.15-21
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    • 2004
  • The machining process of ceramics can be characterized by cracking and brittle fracture. In the machining of ceramics, edge chipping and crack propagation are the principal reasons to cause surface integrity deterioration. Such phenomenon can cause not only poor dimensional and geometric accuracy, but also possible failure of the ceramic parts. Thus, traditional ceramics are very difficult-to-cut materials. To overcome such problems, in this paper, h-BN powder, which gives good cutting property, is added for the fabrication of machinable ceramics by volume of 5, 10, 15, 20, 25 and 30%. The objectives of this paper is to evaluate the fracture phenomenon of the tungsten carbide tool and the variation of surface integrity of the manufactured machinable ceramics under various cutting conditions during end mill machining With CNC machining center.

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A Study on Micro Ultrasonic machining for Brittle Material Using Ultrasonic vibration (초음파 진동을 이용한 취성재료의 가공기술에 관한 연구)

  • Lee Seok-Woo;Choi Heon-Jong;Yi Bong-Gu
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.02a
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    • pp.245-252
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    • 2002
  • Ultrasonic machining technology has been developed over recent years for the manufacture of cost-effective and quality-assured precision parts for several industrial application such as optics, semiconductors, aerospace, and automobile. Ultrasonic machining process is an efficient and economical means of precision machining of ceramic materials. The process is non-thermal, non-chemical and non-electric md hardly creates changes to the mechanical properties of the brittle materials machined. This paper describes the characteristics of the micro-hole of Al2O3 by ultrasonic machining with tungsten carbide tool. The effects of various parameters of ultrasonic machining, including abrasives, machining force and pressure, on the material removal rate, hole quality, and tool wear presented and discussed. The ultrasonic Machining of micro-holes in ceramics has been under taken and the machining mechanism in the ultrasonic machining of ceramics based on the fracture-mechanics concept has been analyzed.

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Optimization of the Turning Conditions of Inconel 718 according to Insert Materials using DOE (실험계획법을 이용한 인서트 종류에 따른 Inconel 718 선삭가공조건 최적화)

  • Shin, Pil-Seon;Kim, Jae-Kyung;Jeon, Euy-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.8
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    • pp.1-8
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    • 2022
  • Inconel 718 is nickel-based and is increasingly being used as a key component in the nuclear, aerospace, and chemical industries which require high fatigue strength and oxidation, because of its excellent corrosion resistance, heat resistance, and wear resistance. It is a heat-resistant alloy which has excellent mechanical properties; however, material deformation, cracking, and shaking occur because of the high cutting temperature accumulated on the cutting surface during cutting processing, and heat accumulated at the insert boundary. Owing to these characteristics, various studies have been conducted, such as developing a tool exclusively for non-deletion, analyzing tool wear, and developing a tool cooling system. However, the optimization of the cutting process is still insufficient. In this study, the optimal process conditions were derived experimentally by cutting conditions according to the insert type during the cutting of Inconel 718.

Processing Characteristics of Multi Layer Diamond Electrodeposition Tool (Multi Layer 다이아몬드 전착 공구의 가공특성에 관한 연구)

  • Cha, Seung-hwan;Yang, Dong-ho;Lee, Sang-hyeop;Lee, Jong-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.3
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    • pp.22-28
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    • 2022
  • In the semiconductor and display component industries, the use of ceramic materials, which are high-strength materials, is increasing for ensuring durability and wear resistance. Among them, alumina materials are used increasingly. Alumina materials are extremely difficult to process because of their high strength; as such, research and development in the area of mineral material processing is being promoted actively to improve their processing. In this study, the processability of an electrodeposition tool is investigated using the electrodeposition method to smoothly process alumina materials. Furthermore, processing is conducted under various processing conditions, such as spindle speed, feed speed, and depth of cut. In addition, the processing characteristics of the workpiece are analyzed based on the tooling.

Characterization of TiN Layered Substrate using Leaky Rayleigh Surface Wave (누설 레일리 표면파를 이용한 TiN 코팅 부재의 특성평가)

  • Kwon, Sung-Duk;Kim, Hak-Joon;Song, Sung-Jin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.1
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    • pp.7-11
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    • 2006
  • Since ceramic layers coated on machinery components inevitably experience the changes in their properties it is necessary to evaluate the characteristics of ceramic coating layers nondestructively for a reliable use of coated components and 4heir remaining life prediction. To address such a need, in the present study, an ultrasonic backward radiation technique is applied to investigate the characteristics of leaky Rayleigh surface waves propagating through the very thin TiN ceramic layers coated on AISI 1045 steel or austenitic 304 steel substrate with three different conditions of surface roughness, coating layer thickness and wear condition. In the experiments performed in the present work, the peak angle and the peak amplitude of ultrasonic backward radiation profile varied sensitively according to three specimen preparation renditions. in fact, this result demonstrates a high possibility of the ultrasonic backward radiation as an effective tool for the nondestructive characterization of the resting layers even in such a thin regime.

Hardness and EDM Processing of MoSi2Intermetallics for High Temperature Ship Engine (고온선박엔진용 MoSi2금속간화합물의 경도와 방전가공특성)

  • 윤한기;이상필
    • Journal of Ocean Engineering and Technology
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    • v.16 no.6
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    • pp.60-64
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    • 2002
  • This paper describes the machining characteristics of the MoSi2--based composites through the process of electric discharge drilling with various tubular electrodes. In addition to hardness characteristics, microstructures of Nb/MoSi2laminate composites were evaluated from the variation of fabricating conditions, such as preparation temperature, applied pressure, and pressure holding time. MoSi2-based composites have been developed in new materials for jet engines of supersonic-speed airplanes and gas turbines for high-temperature generators. These high performance engines may require new hard materials with high strength and high temperature-resistance. Also, with the exception of grinding, traditional machining methods are not applicable to these new materials. Electric discharge machining (EDM) is a thermal process that utilizes a spark discharge to melt a conductive material. The tool electrode is almost -unloaded, because there is n direct contact between the tool electrode and the work piece. By combining a non-conducting ceramic with more conducting ceramic, it was possible to raise the electrical conductivity. From experimental results, it was found that the lamination from Nb sheet and MoSi2 powder was an excellent strategy to improve hardness characteristics of monolithic MoSi2. However, interfacial reaction products, like (Nb, Mo)SiO2and Nb2Si3formed at the interface of Nb/MoSi2, and increased with fabricating temperature. MoSi2composites, with which a hole drilling was not possible through the conventional machining process, enhanced the capacity of ED-drilling by adding MbSi2, relative to that of SiC or ZrO2reinforcements.

A Study on the Surface Roughness Influenced by SM45C Hardness in High Frequency Induction Hardening (고주파열처리에 의한 SM45C 경도가 가공 표면 품위에 미치는 영향에 관한 연구)

  • Kim, W.I.;Heo, S.J.
    • Journal of the Korean Society for Heat Treatment
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    • v.6 no.1
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    • pp.1-8
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    • 1993
  • In this paper, the surface roughness influenced by Sm45C hardness in high frequency induction hardening and mechanical characteristics for the changed Hv 598 part and the unchanged hardness Hv 223 part by use of cermet and ceramic cutting tools was experimentally examined. Finally, we could be had some important results by processing surface roughness on cutting conditions such as cutting speed, feed rate, depth of cut and changes of tool nose radius. The results are summarized as follows. 1. In case of the same cutting condition, the hardness of workpiece was high and acquired the best processing surface roughness when the radius of the tool nose had 0.8 mm and feed rate was 0.04 mm/rev. 2. In case of the hardness of workpiece, though the cutting speed didn't have an effect on processing surface roughness, the less feed rate and the more processing surface roughness improved. On the other hand, the low inside the hardness of workpiece, the more cutting speed and the more feed rate increase, the processing surface of roughness improved. 3. Regardless of the hardness of workpiece, the change of the cutting depth didn't have great effect on the surface roughness. 4. On cutting the high surface hardness part with cutting tools of cermet and ceramic, it can be acquired the higher processing surface roughness because it hadn't been taken effect on cutting speed, In case of the cutting process of the low inside hardness part the two cutting tools have acquired the similar processing surface roughness.

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Histologic changes of pulpal tissue after laser-aided ceramic bracket debonding (레이저를 이용한 도재 브라켓 제거 술식 후 치수의 조직학적 변화)

  • Kim, Yu-Jeong;Lim, Sung-Hoon;Yoon, Young-Joo;Park, Joo-Cheol;Kim, Kwang-Won
    • The korean journal of orthodontics
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    • v.34 no.4 s.105
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    • pp.343-349
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    • 2004
  • Laser-aided debonding has advantages in that the heat produced is localized and controlled, the debonding tool is not heated, and it can be used for the removal of various types of ceramic brackets, regardless of their design. However, the range of safe power usage for laser-aided debonding has not vet been confirmed. The Purpose of this study was to evaluate the histologic changes of pulpal tissue in a rabbit's incisor after Nd-YAG laser-aided ceramic bracket debonding at different levels of power. The result were as follows: 1. At 3-5W Nd-YAG laser power level and 3 seconds of exposure time, the ceramic bracket debonding procedure was not easy. At 5W of power a tie-wing fracture occurred on one bracket during debonding using Weingart plier. The histologic section of pulp represented no adverse changes. 2. At 7-13 W power level and less than 5 seconds of exposure time, the debracketing procedure was done easily and bracket facture did not occur. The histologic section of pulp represented mild and reversible changes. All the results were reversible and no pulpal degeneration or necrosis occurred. Considering the results, it appears that the laser-aided debonding technique is a safe method that does not result in irreversible pulpal changes, softens bracket bonding resin within a saie range of power and exposure time, and is useful for ceramic bracket recycling by lowering the tie- wing fracture rate.

Miniaturized Multilayer Band Pass Chip filter for IMT-2000 (IMT-2000용 초소헝 적층형 대역 통과 칩 필터 설계 및 제작)

  • Lim Hyuk;Ha, Jong-Yoon;Sim, Sung-Hun;Kang, Chong-Yun;Choi, Ji-Won;Choi, Se-Young;Oh, Young-Jei;Kim, Hyun-Jai;Yoon, Seok-Jin
    • Journal of the Korean Ceramic Society
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    • v.40 no.10
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    • pp.961-966
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    • 2003
  • A Multi-Layer Ceramic (MLC) chip type Band-Pass Filter (BPF) using BiNb_0.975/Sb_0.025/ O4 LTCC (Low Temperature Co-fired Ceramics) and MLC processing is presented. The MLC chip BPF has the benefits of low cost and small size. The BPF consists of coupled stripline resonators and coupling capacitors. The BPF is designed to have an attenuation pole at below the passband for a receiver band of IMT-2000 handset. The computer-aided design technology is applied for analysis of the BPF frequency characteristics. The attenuation pole depends on the coupling between resonators and the coupling capacitance. An equivalent circuit and structure of MLC chip BPF are proposed. The frequency characteristics of the manufactured BPF is well acceptable for IMT-2000 application.