• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.171-173
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• 2007

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.193-195
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• 2007

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.339-341
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• 2007

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.349-351
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• 2005

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.393-395
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• 2005

The bonding for Aluminum and Copper in the air is investigated in this study. This bonding method does not include the special process of removing aluminum oxide films. In case of this bending, each metal Is heated at bonding temperature where is above eutectic temperature of Al-Cu system and below melting point of Aluminum. The liquefaction around the bonding surface occurs after the diffusion at solid state of each metal. This phenomenon is predicted by the temperature range above eutectic temperature of Al-Cu equilibrium phase diagram.

• Journal of Welding and Joining
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• 제13권1호
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• pp.103-114
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• 1995

Plasma Transferred arc(PTA) hard facing process has been developed to obtain an overlay weld metal having excellent wear resistance. The effect of Ti, TiSi$_{2}$ and TiC powders addition on the surface of Aluminum alloy 5083 has been investigated with PTA process. This paper describes the result of test the performance of the overlay weld metal. The result can be summarized as follows 1. Intermetallic compound is formed on surface of base metal in Ti or TiSi$_{2}$ powder but the reaction with surface of base metal is little seen in TiC powder. 2. In formation of composite layer on aluminum alloy surface by plasma transferred arc welding process, high melting ceramics like TiC powder is excellent. 3. The multipass welding process is available for formation of high density of powder. But the more number of pass, the less effect of powder, it is considered, and limits of number of pass. 4. By increasing area fraction of TiC powder on Al alloy surface, in especially TiC powder the hardness increase more than 40% area fraction and 88% shows about Hv 700.

• Journal of Welding and Joining
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• 제11권2호
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• pp.74-85
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• 1993

Effect of Si metal powders addition with the plasma transferred arc(PTA) overlaying process on characteristics of the alloyed layer in aluminum alloy(A5083) has been investigated. The overlaying conditions were 175-250A in plasma arc current, 500mm/min in travel speed, the 5-20g/min in powder feeding rate. Main results obtained are summarized as follows. 1)Sufficient size of molten pool on surface of base metal was required for forming an alloyed layer; in a fixed travel, the formation of alloyed layer with clear and beautiful surface depend upon the plasma arc current and powder feeding rate; the greater plasma arc current and the smaller powder feeding rate were, the better bead was formed. Optimum alloyed conditions by which an excellent alloyed bead obtained was 225A in plasma arc current. PTA process made it possible to form an alloyed layer with up to 67wt% Si. 2)Microstructure in the alloyed layer was in accord with prediction from the Al-Si phase diagram 3)The hardness of the alloyed layer increased in proportion to Si content. 4)As volume fraction of primary Si increased, the specific wearness of the alloyed layer was significantly improved. However, no further improvement was found when the volume fraction was greater than about 30%. 5)Utilizing the PTA process, a crack free alloyed layer with maximum hardness of about Hv 310 could be obtained.

• Journal of Welding and Joining
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• 제34권2호
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• pp.67-72
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• 2016

Aluminum alloy is one of light weight material and it is used to make LNG tank and ship. However, in order to weld aluminum alloy high density heat source is needed. In this paper, I-butt welding of Al 5083 with 6mm thickness using Plasma-MIG welding was carried out. The experiment was performed to investigate the influence of plasma-MIG welding parameters such as plasma current, wire feeding rate, MIG-welding voltage and welding speed on the tensile strength of weld. In addition we suggested 3 strength estimation models which are second order polynomial regression model, multiple nonlinear regression model and neural network model. The estimation performance of 3 models was evaluated in terms of average error rate (AER) and their values were 0.125, 0.238, and 0.021 respectively. Neural network model which has training concept and reflects non -linearity was best estimation performance.

• 한국자동차공학회논문집
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• 제13권4호
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• pp.129-134
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• 2005

There is a strong industrial demand for the development of light-weight vehicle to improve fuel efficiency and dynamic performance. The effective method of achieving the weight reduction is to use low-density materials such as aluminum and magnesium. In applying these materials to the vehicle, it is often required to join dissimilar materials such as aluminum and steel. However, conventional joining method, namely resistance spot welding cannot be used in joining dissimilar materials. Self·piercing rivet(SPR) and adhesive bonding is a good alternative to resistance spot welding. In this study, the impact test of double hat-shaped member made by resistance spot welding, SPR and adhesive bonding was performed. As a result, various parameters of crashworthiness were analyzed and evaluated. Also, the applicability of SPR and adhesive bonding as an alternative to resistance spot welding was suggested.

• Journal of Welding and Joining
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• 제7권1호
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• pp.28-35
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• 1989

The fatigue crack growth behavior in GTA butt welded joints of Al-Alloy 5052-H38 was examined using Single Edge Notched(SEN) specimens. It is well known that welding residual stress has marked influence on fatigue crack growth rate in welded structure. In the general area of fatigue crack growth in the presence of residual stress, it is noted that the correction of stress intensity factor (K) to account for residual stress is important for the determination of both stress intensity factor range(.DELTA.K) and stress ratio(R) during a loading cycle. The crack growth rate(da/dN) in welded joints were correlated with the effective stress intensity factor range(.DELTA.Keff) which was estimated by superposition of the respective stress intensity factors for the residual stress field and for the applied stress. However, redistribution of residual stress occurs during crack growth and its effect is not negligible. In this study, fatigue crack growth characteristics of the welded joints were examined by using superposition of redistributed residual stress and discussed in comparison with the results of the initial welding residual stress superposition.