• 제목/요약/키워드: Mechanical Joining

검색결과 1,090건 처리시간 0.023초

A Study on Welding Residual Stress by Numerical Simulation on friction Stir Welding

  • Bang, H.S.;Kim, H.J.;Go, M.S.;Chang, W.S.;Lee, C.W.
    • International Journal of Korean Welding Society
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    • 제2권1호
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    • pp.62-66
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    • 2002
  • The Friction Stir Welding (FSW) is a new joining method that was developed at The Welding Institute (TWI) in England in 1991. It applied heating by the rotational friction and material plastic flow. It was developed as a new joining method to solve the problems of epochally in the welding of Al alloys. In the study, 6000series of Alloy composed of Al-Mg-Si, one of the Al alloys that are utilized for shipbuilding and construction, is selected as a specimen and the numerical is executed against the welded zone of FSW. The material used in this study had the unique properties of strength and anti-corrosion, but since the welded joint of this material is easily softened by the welding heat, FSW is executed and the numerical analysis is carried out around the joint. To examine the mechanical behaviors and properties, F.E.M analysis is executed and the developed thermal-elastic-plastic finite analysis are used.

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MEMS와 전자 패키징을 위한 마이크로 접합 공정 (Microjoining Process for MEMS and Electronic Packaging)

  • 유중돈
    • Journal of Welding and Joining
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    • 제22권4호
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    • pp.24-28
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    • 2004
  • 마이크로 접합 공정은 미세 부품이나 박판의 접합에 사용되며, 이를 위해 다양한 공정이 개발되었다. 최근 MEMS(Micro Electro Mechanical System)활용 범위가 증가하고 있으며, MEMS에 사용되는 미세한 구조물의 접합이나 패키징에 접합 공정이 활용되고 있다. MEMS는 발전 단계이지만 전자 패키징(electronic packaging)은 성숙 단계인 반도체 산업에 사용되고 있다.(중략)

자동차 전장용 무연솔더 및 솔더 접합부의 신뢰성 평가 (Lead-free Solder for Automotive Electronics and Reliability Evaluation of Solder Joint)

  • 방정환;유동열;고용호;윤정원;이창우
    • Journal of Welding and Joining
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    • 제34권1호
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    • pp.26-34
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    • 2016
  • Automotive today has been transforming to an electronic product by adopting a lot of convenience and safety features, suggesting that joining materials and their mechanical reliabilities are getting more important. In this study, a Sn-Cu-Cr-Ca solder composition having a high melting temperature ($>230^{\circ}C$) was fabricated and its joint properties and reliability was investigated with an aim to evaluate the suitability as a joining material for electronics of engine room. Furthermore, mechanical properties change under complex environment were compared with several existing solder compositions. As a result of contact angle measurement, favorable spreadability of 84% was shown and the average shear strength manufactured with corresponding composition solder paste was $1.9kg/mm^2$. Also, thermo-mechanical reliability by thermal shock and vibration test was compared with that of the representative high temperature solder materials such as Sn-3.5Ag, Sn-0.7Cu, and Sn-5.0Sb. In order to fabricate the test module, solder balls were made in joints with ENIG-finished BGA and then the BGA chip was reflowed on the OPS-finished PCB pattern. During the environmental tests, resistance change was continuously monitored and the joint strength was examined after tests. Sn-3.5Ag alloy exhibited the biggest degradation rate in resistance and shear stress and Sn-0.7Cu resulted in a relatively stable reliability against thermo-mechanical stress coming from thermal shock and vibration.

와이어 송급 레이저 금속 3차원 적층 연구동향 (Recent Studies of Laser Metal 3D Deposition with Wire Feeding)

  • 감동혁;김영민;김철희
    • Journal of Welding and Joining
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    • 제34권1호
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    • pp.35-40
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    • 2016
  • Recent developments of Laser metal 3D deposition with wire feeding are reviewed which provide an alternative to powder feeding method. The wire feeding direction, angle and position as well as laser power, wire feeding rate, and deposition speed are found to be key parameters to make quality deposition with high throughput. When compared with the powder feed, the wire feed shows higher material efficiency, higher deposition rate, and smoother surface. Large elongated columnar grains which have epitaxial growth across deposit layers are observed in deposit cross sections. The growth direction is parallel to the thermal gradient during the deposit process. Tensile properties are found to be dependent on the direction due to the anisotropic deposit property. A real-time feedback control is demonstrated to be effective to improve the deposition stability.

Al 6061-T6 합금의 MIG 용접 후 열처리조건에 따른 미세조직 및 기계적 물성 분석 (Analysis of Microstructure and Mechanical Properties According to Heat Treatment Conditions in GMAW for Al 6061-T6 Alloy)

  • 김찬규;조영태;정윤교;강신현
    • Journal of Welding and Joining
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    • 제34권4호
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    • pp.34-39
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    • 2016
  • Recently, aluminum alloy has used various industry, such as automobile, shipbuilding and aircraft because of characteristics of low density and high corrosion resistance. Al 6061-T6 is heat treatment materials so it has high strength and mostly used for assembly by mechanical fastening such as a bolting and riveting. In GMA (Gas Metal Arc) welding of alloy, some defects which are hot cracking, porosity, low-mechanical properties and large heat affected zone is generated, because of high heat conductivity. It reduces mechanical properties. In this study, the major factor effected on properties are analyzed after welding in Al 6061-T6 in GMAW, then optimize heat treatment conditions. Plate of Al 6061-T6 with a thickness of 12 mm is welded in V groove and applied welding method is butt joint. Mechanical properties and microstructure are analyzed according to heat treatment condition. Tensile strength, microstructure and Hardness are evaluated. Result of research appears that Al 6061-T6 applied heat treatment show outstanding mechanical properties.