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  • Title/Summary/Keyword: Hybrid joining

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Effect of Fiber Orientation on Failure Strength Properties of Natural Fiber Reinforced Composites including Adhesive Bonded Joints (접착제 접합된 자연섬유강화 복합재료의 파괴 강도특성에 미치는 섬유방향의 영향)

  • Im, Jae-Gyu;Yun, Ho-Cheol;Lee, Sang-Yong;Renliang, Wang
    • Proceedings of the KWS Conference
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    • 2005.11a
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    • pp.94-96
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    • 2005
  • This paper is concerned with a fracture strength study of composite adhesive lap joints. The tensile and peel tests were carried out on specimen manufactured hybrid stacked composites such as the polyester and bamboo natural fiber layer. The main objective of the work was to test the failure strength of adhesive bonded joints using hybrid stacked composites with a polyester and bamboo natural fiber layer adjacent to the fiber orientation. From results, the load directional orientation, small amount and low thickness of bamboo natural fiber layer have a good effect on the tensile and peel strength of natural fiber reinforced composites. and these characters are have a great influence on fracture strength and failure shape of adhesive bonded joints using hybrid stacked composites in the difference of fiber orientation.

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Power Module Packaging Technology with Extended Reliability for Electric Vehicle Applications (전기자동차용 고신뢰성 파워모듈 패키징 기술)

  • Yoon, Jeong-Won;Bang, Jung-Hwan;Ko, Yong-Ho;Yoo, Se-Hoon;Kim, Jun-Ki;Lee, Chang-Woo
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.4
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    • pp.1-13
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    • 2014
  • The paper gives an overview of the concepts, basic requirements, and trends regarding packaging technologies of power modules in hybrid (HEV) and electric vehicles (EV). Power electronics is gaining more and more importance in the automotive sector due to the slow but steady progress of introducing partially or even fully electric powered vehicles. The demands for power electronic devices and systems are manifold, and concerns besides aspects such as energy efficiency, cooling and costs especially robustness and lifetime issues. Higher operation temperatures and the current density increase of new IGBT (Insulated Gate Bipolar Transistor) generations make it more and more complicated to meet the quality requirements for power electronic modules. Especially the increasing heat dissipation inside the silicon (Si) leads to maximum operation temperatures of nearly 200C. As a result new packaging technologies are needed to face the demands of power modules in the future. Wide-band gap (WBG) semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) have the potential to considerably enhance the energy efficiency and to reduce the weight of power electronic systems in EVs due to their improved electrical and thermal properties in comparison to Si based solutions. In this paper, we will introduce various package materials, advanced packaging technologies, heat dissipation and thermal management of advanced power modules with extended reliability for EV applications. In addition, SiC and GaN based WBG power modules will be introduced.

Process Development for Automotive Hybrid Hood using Magnesium Alloy AZ31B Sheet (마그네슘 합금 AZ31B 판재를 이용한 자동차 하이브리드 후드 개발 프로세스)

  • Jang, D.H.
    • Transactions of Materials Processing
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    • v.20 no.2
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    • pp.160-166
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    • 2011
  • Weight reduction while maintaining functional requirements is one of the major goals in the automotive industry. The use of lightweight magnesium alloys offers great potential for reducing weight because of the low density of these alloys. However, the formability and the surface quality of the final magnesium alloy product for auto-body structures are not acceptable without a careful optimization of the design parameters. In order to overcome some of the main formability limitations in the stamping of magnesium alloys, a new approach, the so-called "hybrid technology", has been recently proposed for body-in-white structural components. Within this approach, necessary level of mechanical joining can be obtained through the use of lightweight material-steel adhesion promoters. This paper presents the development process of an automotive hybrid hood assembly using magnesium alloy sheets. In the first set of material pairs, the selected materials are magnesium alloy AZ31B alloy and steel(SGCEN) as inner and outer panels, respectively. In order to optimize the design of the inner panel, the stamping process was analyzed with the finite element method (FEM). Laser welding by CW Nd:YAG were used to join the magnesium alloy sheets. Based on the simulation results and mechanical test results of the joints, the determination of die design variables and their influence on formability were discussed. Furthermore, a prototype based on the proposed design was manufactured and the static stiffness test was carried out. The results demonstrate the feasibility of the proposed hybrid hood with a weight reduction of 25.7%.

A Study on the Weldability for fillet joint of light weight alloy 5mm Al 5083 using Hybrid(CW Nd:YAG Laser+MIG) Welding

  • Park, Ho-Kyoung;Bang, Hee-Seon;Rajesh, S.R.;Oh, Chong-In;Bang, Han-Sur
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.216-218
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    • 2006
  • The application of aluminium alloy is increasing for lightweight and high quality transport vehicle. In this study, therefore, it is intended to apply the high speed hybrid welding method for marine grade aluminium alloy(A5083) used for shipbuilding that consists of 3 kW CW Nd:YAG laser and MIG welding process. For this purpose, the characteristics of process parameters(laser & arc combine angle and focal position of hybrid head to specimen) are investigated for hybrid fillet joint. This study also describes determination of heat distribution using finite element model of the T-joint fillet weld using the in-house solver which has been validated for different type of welding problems.

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Interest Based Clustering Mechanism for Hybrid P2P (하이브리드 P2P를 위한 관심분야 기반 클러스터링)

  • Lee, Lee-Sub
    • Journal of the Korea Society for Simulation
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    • v.15 no.1
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    • pp.69-75
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    • 2006
  • P2P services occupy more then 50% of the internet traffics. A huge number of query packets are generated since pure P2P based models rely on message flooding for their query mechanisms. In this study, the numbers of query messages generated in the pure P2P and hybrid P2P model are analyzed. The results show that hybrid P2P models also could suffer from message flooding. To reduce the message flooding, this study proposes an interest based clustering mechanism for hybrid P2P services. By applying this clustering algorithm, it could reduce 99.998% of the message flooding. The proposed algorithm also reduces the cost of the joining operations by storing previous supernodes.

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The Effect of Tool Geometry on the Mechanical Properties in a Friction Stir Welded Lap Joint between an Al Alloy and Zn-coated Steel (알루미늄 합금과 아연도금강판의 이종 겹치기 마찰교반접합에서 기계적성질에 미치는 Tool Geometry의 영향)

  • Kim, Nam-Kyu;Kim, Byung-Chul;Jung, Byung-Hoon;Song, Sang-Woo;Nakata, K.;Kang, Chung-Yun
    • Korean Journal of Metals and Materials
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    • v.48 no.6
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    • pp.533-542
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    • 2010
  • The specific motivation for joining an Al alloy and Zn-coated steel arises from the need to save fuel consumption by weight reduction and to enhance the durability of vehicle structures in the automobile industry. In this study, the lap joining A6K31 Al alloy (top) and SGARC340 Zn-coated steel (bottom) sheets with a thickness of 1.0 mm and 0.8 mm, respectively, was carried out using the friction stir weld (FSW) technique. The probe of a tool did not contact the surface of the lower Zn-coated steel sheet. The friction stir welding was carried out at rotation speeds of 1500 rpm and travel speeds of 80~200 mm/min. The effects of tool geometry and welding speed on the mechanical properties and the structure of a joint were investigated. The tensile properties for the joints welded with a larger tool were better than those for the joints done with a smaller tool. A good correlation between the tensile load and area of the welded region were observed. The bond strength using a larger tool (M4 and M3) decreased with an increase in welding speed. Most fractures occurred along the interface between the Zn-coated steel and the Al alloy. However, in certain conditions with a lower welding speed, fractures occurred at the A6K31 Al alloy.

Basic Welding Characteristics by Nd-YAG Laser Beam on AH32 (선급강재의 레이저 용접특성에 관한 기초실험 - HYBRID 용접시 LASER-ARC거리 변화에 따른 용융특성 변화에 관한 실험)

  • Bang, Ban-Sur;Joo, Sung-Min;Kim, Young-Pyo;Kim, Hyung;Katayama, Seiji
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.279-283
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    • 2003
  • As the state of the art in recent years Laser-Arc Hybrid welding is tried actively because of its various economical and technical advantages. In this study, melting tendencies according to the variation of laser-arc distance are investigated in case of YAG laser-TIG Hybrid welding process of AH32 ship structural steel. Nd-YAG laser with a laser beam power of 3KW is used and varied laser-arc distance 0mm to 10mm with fixing the TIG current as l00A. There is certain distance between laser and TIG elecrode to improve welding heat input and also increase the penetration.

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Experimental Study of the Seismic Performance of CJS Hybrid Structural Systems Connected to the CFT Column (CFT와 합성보로 이루어진 CJS합성구조시스템의 내진성능 실험 연구)

  • Lim, Chang Gue;Shin, Jiuk;Moon, A Hae;Kim, Yong Nam;Lee, Kihak
    • Journal of the Earthquake Engineering Society of Korea
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    • v.26 no.2
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    • pp.83-93
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    • 2022
  • In this study, to verify the structural performance of the Composite Joint System (CJS) hybrid structural model, a cyclic load test was performed and evaluated and verified through the test. To verify the structural performance of the CJS hybrid structural systems' joint and evaluate the seismic performance, four three-dimensional real-size specimens were developed with three internal beam-column specimens and one external beam-column specimen. The three interior column specimens were classified by different methods of joining the upper column and lower column, and the same bonding method as the primary specimen was used for the exterior column. The structural performances in terms of drift, strength, and energy dissipation capacity were analyzed and compared based on the experimental results. From the displacement-based loading experiment, all specimens showed a lateral drift of 4.0% without any significant strength drop and stable energy dissipation capacity.

A study on tensile shear characteristics for weld-bonded 1.2GPa grade TRIP steels with changes in nugget diameter for automotive body application (자동차 차체용 1.2GPa급 TRIP 강의 Weld-bond부 너깃경에 따른 인장전단특성에 관한 연구)

  • Choi, Ildong;Park, Jiyoun;Kim, Jae-Won;Kang, Mun-Jin;Kim, Dong-Cheol;Kim, Jun-Ki;Park, Yeong-Do
    • Journal of Welding and Joining
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    • v.33 no.2
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    • pp.69-77
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    • 2015
  • High strength steels have been continually being developed to improve in fuel economy in automotive and ensure safety of passengers. New bonding and welding methods have been required for improving weldability on high strength steels. In this study, resistance spot welding and Weld-bond with nugget diameters of 4.0mm, 5.0mm, 6.0mm and 7.0mm were produced and tested, respectively. In order to confirm the effect of nugget diameters on tensile shear characteristic of the Weld-bond, tensile shear characteristics of Weld-bond were compared with those of resistance spot welding and adhesive bonding. Peak load of Weld-bond were increased as the nugget diameter increases. After appearing maximum peak load continuous fracture followed with second peak owing to load being carried by resistance spot weldment. Fracture modes of the adhesive layer in Weld-bond fractures were represented by mixed fracture mode, which are cohesive failure on adhesive part and button failure at resistance spot welds. The results showed that the tensile shear properties can be improved by applying Weld-bond on TRIP steel, and more apparent with nugget diameter higher than 5t.

Recent developments and challenges in welding of magnesium to titanium alloys

  • Auwal, S.T.;Ramesh, S.;Tan, Caiwang;Zhang, Zequn;Zhao, Xiaoye;Manladan, S.M.
    • Advances in materials Research
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    • v.8 no.1
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    • pp.47-73
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    • 2019
  • Joining of Mg/Ti hybrid structures by welding for automotive and aerospace applications has attracted great attention in recent years due mainly to its potential benefit of energy saving and emission reduction. However, joining them has been hampered with many difficulties due to their physical and metallurgical incompatibilities. Different joining processes have been employed to join Mg/Ti, and in most cases in order to get a metallurgical bonding between them was the use of an intermediate element at the interface or mutual diffusion of alloying elements from the base materials. The formation of a reaction product (in the form of solid solution or intermetallic compound) along the interface between the Mg and Ti is responsible for formation of a metallurgical bond. However, the interfacial bonding achieved and the joints performance depend significantly on the newly formed reaction product(s). Thus, a thorough understanding of the interaction between the selected intermediate elements with the base metals along with the influence of the associated welding parameters are essential. This review is timely as it presents on the current paradigm and progress in welding and joining of Mg/Ti alloys. The factors governing the welding of several important techniques are deliberated along with their joining mechanisms. Some opportunities to improve the welding of Mg/Ti for different welding techniques are also identified.