Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Welding and Joining
Journal Basic Information
Journal DOI :
The Korean Welding and Joining Society
Editor in Chief :
Volume & Issues
Volume 20, Issue 6 - Dec 2002
Volume 20, Issue 5 - Oct 2002
Volume 20, Issue 4 - Aug 2002
Volume 20, Issue 3 - Jun 2002
Volume 20, Issue 2 - Apr 2002
Volume 20, Issue 1 - Feb 2002
Selecting the target year
Vision for Welding Industry in USA
Kim, Dong-Sub ;
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 407~413
Review of Welding Research in Japan
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 414~422
Vision for Welding Industry in China
Park, Dong-Guang ;
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 423~426
No Abstract, See Full-text
Cracking in Welds and Its Prevention(IV) - Hot Cracking in Welds(III) -
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 427~428
Evaluation Methods for Cold Crack Susceptibility of Deposited Metal
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 429~436
Evaluation of Metallurgical Characteristics and Strength on Soldered Joint
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 437~442
Principles and Applications of Thermal Spraying Techniques
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 443~450
The Microstructure of Fiber Reinforced Plasma Sprayed Coatings
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 451~458
Cold Gas Dynamic Spraying Process
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 459~466
Corrosion Protection Technology of Steel Structures Applying Zn-Al Normal Temperature Metal Spraying System
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 467~475
Trend of the Thermal Spraying /Overlay Welding Technology in Korea
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 476~483
Analysis of Keyhole Formation and Stability in Laser Spot Welding
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 484~490
The formation and stability of stationary laser weld keyholes were investigated using a numerical simulation. The effect of multiple reflections in the keyhole was estimated using the ray tracing method, and the free surface profile, flow velocity and temperature distribution were calculated numerically. In the simulation, the keyhole was formed by the displacement of the melt induced by evaporation recoil pressure, while surface tension and hydrostatic pressure opposed cavity formation. A transition mode having the geometry of the conduction mode with keyhole formation occurred between the conduction and keyhole modes. At laser powers of 500W and greater, the protrusion occurred on the keyhole wall, which resulted in keyhole collapse and void formation at the bottom. Initiation of the protrusion was caused mainly by collision of upward and downward flows due to the pressure components, and Marangoni flow had minor effects on the flow patterns and keyhole stability.bility.
Analysis of Dynamic Characteristics of Molten Drop and Pulse Condition in Pulsed-GMAW
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 491~497
Dynamic behavior of the molten drop during the peak period in the pulsed-GMAW is simulated in this work using the VOF(volume of the fluid) algerian. The dynamic characteristics of molten drop such as minimum radius, average velocity and displacement of mass center were computed as well as the internal pressure and velocity. The minimum and maximum peak durations for detaching a drop were calculated.. The result of Analysis reveals that peak current and volume of pendant drop are important factors which affecting drop detachment. A simplified model of constant acceleration is proposed to describe the behavior of molten drop during peak current, and its results agree with the experimental results.
Effect of Plasma Treatment on the Bond Strength of Sn-Pb Eutectic Solder Flip Chip
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 498~504
Fluxless flip chip bonding process using plasma treatment instead of flux was investigated. The effect of plasma process parameters on tin-oxide etching characteristics were estimated with Auger depth profile analysis. The die shear test was performed to evaluate the adhesion strength of the flip chip bonded after plasma treatment. The thickness of oxide layer on tin surface was reduced after Ar+H2 plasma treatment. The addition of H2 improved the oxide etching characteristics by plasma. The die shear strength of the plasma-treated Sn-Pb solder flip chip was higher than that of non-treated one but lower than that of fluxed one. The difference of the strength between plasma-treated specimen and non-treated one increased with increase in bonding temperature. The plasma-treated flip chip fractured at solder/TSM interface at low bonding temperature while the fracture occurred at solder/UBM interface at higher bonding temperature.
A Study on the Soldering Characteristics of Sn-Ag-Bi-In Ball in BGA
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 505~509
Pb is considered to be eliminated from solder, due to its toxicity. However, melting temperatures of most Pb-free solders are known higher than that of Sn37Pb. Therefore, there is a difficulty to apply Pb-free solders to electronic industry. Since Sn3Ag8Bi5In has relatively lower melting range as
, on this study. Wettability and soldering characteristics of Sn3Ag8Bi5In solder in BGA were investigated to solve for what kind of problem. Zero cross time, wetting time, and equilibrium force of Sn3Ag8Bi5In solder for Cu and plated Cu such as Sn, Ni, and Au/Ni-plated on Cu were estimated. Plated Sn on Cu showed best wettability for zero cross time, wetting time and equilibrium farce. Shear strength of the reflowed joint with Sn3Ag8Bi5In ball in BGA was investigated. Diameter of the ball was 0.5mm, UBM(under bump metallurgy) was
and flux was RMA type. For the reflow soldering, the peak reflow temperature was changed in the range of
, and conveyor speed was 0.6m/min.. The shear strength of Sn3Ag8Bi5In ball showed similar level as those of Sn37Pb. The soldered balls are aged at
for 36days and their shear strengths were evaluated. The shear strength of Sn3Ag8Bi5In ball was increased from 480gf to 580gf by aging for 5 days.
Effects of the Gap and the Speed on the Lap-Joint
Laser Welding of Automotive Steel Sheets
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 510~516
Recently the laser welding technology has been applied increasingly for the automotive bodies. But the lap joint laser welding for 3 dimensional automotive body is new while the butt joint laser welding is well known as the tailored blank technology. In this study, the process window was found for the full penetration welding of the lap joint of the 1mm-thick high strength steel sheets. The limit curves and characteristic curves were suggested to define the boundaries and the contour lines in a space of the welding speed and the gap size. The characteristics of the weld sectional geometry were used to determine the limit curves. They are bead width, penetration depth and sectional area. After the observed data was analysed carefully, it was noticed that there was a transition point at which the sectional shape was changed and the bead area jumped as the welding speed was increased. Also a new concept of 'input energy Per volume' was suggested to distinguish the difference at the transition Point. The difference of sectional areas at the transition point can be related to the dynamic keyhole phenomena.
Effect of the Welding Methods on the Characteristics of Overlaying Seat-surfaces of Engine Valves
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 517~524
An overlaying of the seating surfaces of engine valves by OAW, GTAW or PTA weldings are common practice. The OAW method of a lower torch energy density compared to GTAW and PTA methods produces smoother deposits but the pain size at the vicinity of the interface is increased remarkably up to
(that of base metal is about
). It's grain coarsening and the solute dilution are related to the decarburizing during OAW could be minimized by reducing the preheating temperature and by maintaining the carbide precipitates in base metal prior to welding. The formation of columnar structures and carbide precipitation zone in the vicinity of the GTAW welded interface, because of the high heat concentration, causes weakened zone on the valve seat face. The width of the reaction boundary zone is about
for PTA and GTAW overlaying, and about
for OAW welding. The smaller width of the reaction boundary zone is the less the solute-dilution rate. Thereby PTA welding may be recommended for overlaying of the seating surfaces.
A Study on Pulsed Nd:YAG Laser Welding of Electron Gun in Braun Tubes (I) - Characteristics of Beam Output Energy and Optical Parameters -
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 525~534
During laser spot welding of the braun tube electron gun, phenomena such as serious spattering and oxidative reaction, etc. were occurred. The spatter occurred from weld pool affects the braun tube, namely it blocks up a very small hole on the shadow mask and causes short circuit between two roles of the electron gun. We guessed that high power density and oxidative reaction are main sources of these problems. So, we studied to prevent and to reduce spatter occurring in spot welding of the braun tube electron gun using pulsed Nd:YAG laser. The characteristics of laser output power was estimated, and the loss of laser energy by optical parameter and spatter was measured by powermeter. The effects of welding parameters, laser defocused distance and incident angle, were investigated on the shape and penetration depth of the laser welded bead in flare and flange joints. From these results, the laser peak power was a major factor to control penetration depth and to occur spatter. It was found that the losses of laser energy by optic parameter and sticked spatter affect seriously laser weldability of thin sheets. The deepest penetration depth is gotten on focal position, and a "bead transition" occurred with a slight displacement of focal position relative to the workpiece surface and the absorption rate of the laser energy is affected by the shape factor of the workpiece. When we changed the incident angle of laser beam, the penetration depth was decreased a little with increasing of the incident angle, and the bead width was increased. The spattering was prevented by considering laser beam energy and incident angle.ent angle.
A Study on the Thermal Behavior of Friction Stir Welding in hi 6061 Alloys
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 534~537
In the various industry such as shipbuilding and automobile, etc., Al-alloys are used to reduce weight and improve economical efficiency, and they are mainly utilized in the process of Friction Stir Welding (FSW). A number of studies have been carried out on the metallurgical characteristics of friction stir welding In Al-alloys. However, research on the thermal behavior of FSW by using numerical analysis is not sufficient in the domestic and abroad. In this paper, therefore, numerical simulation was used to find out thermal behaviour of FSW by finite element method. We considered heat source that occurred by friction between tool shoulder including pin and base metal. To confirm the result of simulation, macrostructure is examined and compared after welding. The result of numerical simulation shows that Al-alloy is welded under a melting point of Al around pin by FSW.
A Study on Weldability Criteria of Mash Seam Tailored Blank Welds in the Ultra-low Carbon Steel Applied on Automotive Body
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 538~543
M/S TB(Mash Seam Tailored Blank) is a production method for blanks by welding together blanks of different material, thickness and coating, and is an attractive method for manufacturing car body because it makes parts lighter and can save the cost and time to manufacture. However, there have not been quantified criteria to evaluate the quality of TB weld. This study introduced FHR (failure height ratio) in order to assess formability or/and weldability of the M/S welds and the applicability of FHR was confirmed by actual auto body forming and FLD tests. Furthermore, a new parameter, HN(heat number) based on the heat input of "
" was proposed and assessed. It was found that the concept of HN could be utilized to evaluate the soundness of M/S welds without any destructive tests.ive tests.
The Analysis of Welding Deformation in Arc-spot Welded Structure (I) - Temperature Monitoring and Heat Transfer Analysis -
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 544~550
Arc-spot welding is generally used in joining of precise parts such as case and core in electronic compressor. It is important to control joining deformation in electronic compressor because clearance control in micrometer order is needed for excellent airtightness and anti-nose. The countermeasures far this deformation in field have mainly been dependent on the rule of try and error by operator's experience because of productivities. For control this deformation problem without influence on productivities, development of exact simulation model should be needed. In this study, to solve this deformation problem in arc-spot welded structure with case and core, we intend to make a simulation model that is able to predict deformation in precise order by tuning and feedback between sensing data and simulation results. This paper include development of heat input model for arc-spot welding, temperature monitoring and make a heat transfer model using sensing data in product.
A Study on Solid Particle Erosion Wear Characteristics of High Cr White Iron Hardfacing by Response Surface Method
Journal of Welding and Joining, volume 20, issue 4, 2002, Pages 551~556
Solid particle erosion wear characteristics of high Cr white iron hardfacing were investigated using the erosion wear test method according with the ASTM G76-95. Wear experiments, where the blast angle, blast distance and blast pressure were selected as test variables, were planned and analyzed by response surface method (RSM to evaluate the wear loss statistically and quantitatively. The measured wear losses well coincided with the calculated ones by the experimental equation. The wear loss of high Cr cast iron hardfacing was increased with blasting pressure, but affected in a complicated way by the blasting angle and distance. Erosion wear of high Cr cast iron hardfacing could be well predicted by RSM analysis of wear variables.