• Journal of Welding and Joining
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• 제2권1호
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• pp.1-3
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• 1984

$CO_2$ 편면 용접은 편면 잠호 용접과 함께 작업 능률 향상, 작업 환경 개선 등의 잇점을 가지고 있어 국내의 조선소에서 많이 사용하고 잇는 용접 기법 중의 하나이다. $CO_2$ 편면 용접을 시공하기 위해서 가접보다는 strong back을 많이 사용하는데 strongback의 부착은 전 면과 후면에 부착시키는 2가지 경우가 있다. strongback을 전면에 부착할 경우 아아크는 strongback의 위치마다 중단된다. 후면에 부착할 경우 strongback으로 인한 아아크 중단은 없 어지나 용접사가 자세를 바꾸지 않고 한 번에 용접할 수 있는 최대 용접장은 1m정도이다. 이때 용접장 1m마다 아아크는 중단되게 된다. 이러한 아아크 중단부에는 용착 금속의 수축으로 인한 수축공(shrinkage hole)이 내재되어 용접 금속의 품질을 떨어뜨리므로 이를 제거하기 위해 용접 중 또는 용접 후에 gouging을 해야할 필요가 생긴다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 추계산학기술 심포지엄 및 학술대회 발표논문집
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• pp.169-172
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• 2001

다층 MEMS구조의 기초기판쌍 소재로 쓰일 수 있는 Si∥SiO₂/Si₃N₄∥Si 기판쌍의 직접접합 가능성을 확인하기 위해서 2000Å-SiO₂와 500Å-Si₃N₄층을 가진 직경 10cm의 실리콘 기판을 각각 친수성 및 소수성 표면세척을 하고 청정분위기에서 경면끼리 가접을 실시하였다. 가접된 기판쌍을 통상의 박스형 전기로를 이용하여 400, 600, 800, 1000, 1200℃ 범위에서 2시간 동안 가열하여 접합을 완료하였다. 완성된 기판쌍을 적외선분석기를 이용하여 접합면적을 확인하였고, 면도칼 삽입법으로 접합계면에너지를 측정하였다. 실험온도 범위 내에서 Si∥SiO₂/Si₃N₄∥Si 기판쌍은 1000℃ 이상에서 접합계면에너지는 2,344mJ/㎡을 나타냈으며, 이는 기존의 Si/Si의 동종접합기판쌍과 동등한 수준의 접합강도로서 부가가치가 큰 새로운 조합의 기판쌍 제조가 가능하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.289-291
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• 2004

The purpose of this study is to identify the effects of the length of tack weldment on the rotational distortion at the one side SA butt weldment using experiment. The maximum rotational distortion at the end of the SA weldment decrease with an increase in the length of tack weld length, while the maximum rate of the distortion increases. This result indicates that the increase of the length of the tack weldment at the one-side SA butt weldment does not prevent the hot cracks.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.304-306
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• 2006

Positioning the workpiece accurately and preventing the weld distortion, tack welding is often performed before main welding in the construction of welded structures. The weld bead size of the tack weld is determined according to the workpiece thickness, weld length, weld joint type etc. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually adopted for the uniform weld bead profile. In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method uses the response surface analysis in which the leg length and the reinforcement height of weld bead were chosen as the quality variables of weld bead profile. The overall desirability function, which was combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. From the result, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• Journal of Welding and Joining
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• 제24권5호
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• pp.29-36
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• 2006

In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method used the response surface analysis in which the leg length and the reinforcement height were chosen as the quality variables of the weld bead profile. The overall desirability function, which was combined desirability function fur the two quality variables, was employed as the objective function for getting the optimal welding condition. In the experiments, the target values of the leg length and the reinforcement height are 6m and zero respectively for the horizontal fillet weld of 10mm thickness mild steel. The optimal welding conditions could predict the weld bead profile(leg length and reinforcement height) as 6.00mm and 0.19mm without tack weld and 6.00mm and 0.48mm with tack weld. from a series of welding test, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• 대한조선학회논문집
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• 제49권1호
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• pp.87-92
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• 2012

Alignment of the main plates during the tack welding is essential to block assembly since most of the curved blocks and outfitting parts are assembled on the jigs and fixtures. Tact welding of main plates is the initial process of the curved hull block assembly. Due to the heavy weight of the main plates it is difficult to locate the plate on the accurate position of the jig and fixtures before welding. The conventional masonry process requires much time and manual work in order to achieve the accurate alignment. This labour-intensive process results in relatively high errors and correction works. Due to their larger dimensions and heavier weights, these hull blocks are not ergonomically desirable and, therefore, various mechanical devices such as hydraulic balancers or hydraulic jigs are used for the plate alignment. In this study, the position-sensing scheme implemented by sensors is presented in order to align the main plates on the accurate position during the hull block assembly. Integrating the Infrared photo sensors and micro processor unit, a small scaled prototype of the position-sensing module is developed to determine the alignment of main plates.