• Title/Summary/Keyword: Joining strength

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A Study on the Spot Weldability of High Strength Steel Sheet and Two Stories Galvannealed High Strength Steel Sheet (고장력강판 및 2층아연도금된 고장력 강판의 점용접성에 관한 연구)

  • 신현일;강성수
    • Journal of Welding and Joining
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    • v.12 no.3
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    • pp.56-62
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    • 1994
  • The spot weldability of high strength steel sheet and two stories galvannealed high strength steel sheet has been studied. 1) Tensile shear strength decreased inversely as welding current increased over 12KA in the case of two stories galvannealed high strength steel sheet. 2) When heat flux input over 12KA, hardening region become narrow in case of two stories galvannealed high strength steel sheet. 3) The size of hardening region affect the strength of nuggets.

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A Study on Joining of 3D Thermoset and Biodegradable Polymers (열경화성 3D 프린트 몰드와 생분해성 소재 접합에 관한 연구)

  • Yoon, Sung Chul;Ma, Jae Kwon;Bang, Dae Wook;Choi, Hae Woon
    • Journal of Welding and Joining
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    • v.32 no.4
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    • pp.20-25
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    • 2014
  • Laser heat source was applied on 3D poly urethane model built by 3D printer and cellulous acetate for joining. A diode laser with 808nm wavelength was transmitted through the 3D model and applied on the boundary of ABS/Acetate and 3D poly urethane model. Based on the experimental result, the ABS and 3D built poly-urethane polymers was successfully joined, but the mechanical strength was not enough at the joining boundaries in the range of 6watt to 8watt of laser heat source. However, biodegradable acetate was successfully joined without damaging the 3D built model and mechanical strength was properly achieved. The optimum laser power was found between 5watt and 8watt with scanning speed of 500mm/min, 700mm/min and 1,000mm/min. Based on the SEM analysis the filling mechanism was that the applied pressure on 3D built model squeezed the fluidic thermoplastics, ABS and acetate, into the structure of 3D model. Therefore soundness of joining was strongly depending on the viscosity of thermoplastics in polymers. The developed laser process is expected to increase productivity and minimize the cost for the final products.

Characteristics of Shear Strength for joined SiC-SiC Ceramics (SiC세라믹스 동종재 접합재의 전단강도 특성 평가)

  • Yoon, Han Ki;Jung, Hun Chea;Hinoki, T.;Kohyama, A.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.5
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    • pp.483-487
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    • 2014
  • In this study, joining methods with SiC powder as the joining adhesives were studied in order to avoid the residual stresses coming from CTE (Coefficient of Thermal Expansion) mismatch between substrate and joining layer. The shear strength and microstructure of joined material between SiC substrates are investigated. The commercial Hexoloy-SA (Saint-Gobain Ceramics, USA) used in this work as substrate material. The fine ${\beta}$-SiC nano-powder which the average particle size is below 30 nm, $Al_2O_3$, $Y_2O_3$, and $SiO_2$ were used as joining adhesives. The specimens were joined with 20MPa and $1400-1900^{\circ}C$ by hot pressing in argon atmosphere. The shear test was performed to investigate the bonding strength. The cross-section of the joint was characterized by using an optical microscope and scanning electron microscopy (SEM).

Characteristics of Adhesive bonded Joints of Steels for Automobile(I) (자동차용 강판의 접착특성 - 접착부위 접합 강도와 영향인자 -)

  • 윤병현;권영각
    • Journal of Welding and Joining
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    • v.13 no.2
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    • pp.106-114
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    • 1995
  • The characteristics of adhesive bonded joint of steels for automobile were investigated. Shear and tear strength were tested and analyzed for the joints of cold rolled steel sheets bonded with three kinds of epoxy and urethane based adhesive. The results showed that the tensile shear strength and the tear strength of adhesive joint were affected by the shape of adhesive joint such as the length and width of adhesive joint. The thickness of adhesive layer was very important factor affecting the bonding strength. The shear strength increased with decrease of the thickness of adhesive layer, while the tear strength decreased as the thickness of adhesive layer decreased. In comparison with the strength of spot welded joint, the shear strength of adhesive Joint was higher than that of spot welded joint, but the tear strength of adhesive Joint was lower than that of spot welded joint.

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Joining characteristics of BGA solder bump by induction heating (유도가열에 의한 BGA 솔더 범프의 접합특성에 관한 연구)

  • 방한서;박현후
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.86-88
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    • 2003
  • The characteristic of induction heating solder bump(solder ball: Sn-37Pb, Sn-3.5Ag, Sn-3.0Ag-0.5Cu) has analyzed in this paper. The initial condition of induction heating depends on the time and current. The shape of lead-free solder bump is better than lead solder. The shear strength of lead solder bump has decreased with aging time. The average of shear strength of solder bump is about 10N, 11N, and 11N respectively. The lead-free solder bump's shear strength is better than lead solder and varies irregularly with aging time.

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