Effect of Arc Pressure on the Digging Process in Variable Polarity Plasma Arc Welding of A5052P Aluminum Alloy

Xu, Bin; Tashiro, Shinichi; Jiang, Fan; Chen, Shujun; Tanaka, Manabu

doi:10.3390/ma12071071

Cited by 17 publications

(4 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, in PAW, the arc pressure at 150 A was measured by Xu et al [ 44 ] and Li et al [ 21 ]. It was reported that the maximum values were 3.3 kPa and 3.5 kPa, respectively.…”

Section: Plasma Arc Characteristicsmentioning

confidence: 99%

Interaction Mechanism of Arc, Keyhole, and Weld Pool in Keyhole Plasma Arc Welding: A Review

Tashiro

2024

Materials

Self Cite

View full text Add to dashboard Cite

The Keyhole Plasma Arc Welding (KPAW) process utilizes arc plasma highly constricted by a water-cooled cupper nozzle to produce great arc pressure for opening a keyhole in the weld pool, achieving full penetration to the thick plate. However, advanced control of welding is known to still be difficult due to the complexity of the process mechanism, in which thermal and dynamic interactions among the arc, keyhole, and weld pool are critically important. In KPAW, two large eddies are generally formed in the weld pool behind the keyhole by plasma shear force as the dominant driving force. These govern the heat transport process in the weld pool and have a strong influence on the weld pool formation process. The weld pool flow velocity is much faster than those of other welding processes such as Tungsten Inert Gas (TIG) welding and Gas Metal Arc (GMA) welding, enhancing the heat transport to lower the weld pool surface temperature. Since the strength and direction of this shear force strongly depend on the keyhole shape, it is possible to control the weld pool formation process by changing the keyhole shape by adjusting the torch design and operating parameters. If the lower eddy is relatively stronger, the heat transport to the bottom side increases and the penetration increases. However, burn-through is more likely to occur, and heat transport to the top side decreases, causing undercut. In order to realize further sophistication of KPAW, a deep theoretical understanding of the process mechanism is essential. In this article, the recent progress in studies regarding the interaction mechanism of arc, keyhole, and weld pool in KPAW is reviewed.

show abstract

“…On the other hand, in PAW, the arc pressure at 150 A was measured by Xu et al [ 44 ] and Li et al [ 21 ]. It was reported that the maximum values were 3.3 kPa and 3.5 kPa, respectively.…”

Section: Plasma Arc Characteristicsmentioning

confidence: 99%

Interaction Mechanism of Arc, Keyhole, and Weld Pool in Keyhole Plasma Arc Welding: A Review

Tashiro

2024

Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thermal joining processes generally involve the butt welding of the busbars (Figure 1d) by laser beam welding [9], electron beam welding [10], and plasma arc welding [11]. Despite the current-carrying capacity being practically unaffected by these joints, their use is constrained by the low absorptivity of the busbar materials, the surface preparation requirements, the large busbar thicknesses, and the difficult applicability in situ.…”

Section: Introductionmentioning

confidence: 99%

Injection Lap Riveting of Aluminum Busbars—A Thermo-Electro-Mechanical Investigation

Pragana

Sampaio

Bragança

et al. 2022

JMMP

View full text Add to dashboard Cite

This paper presents a new mechanical joining process to assemble aluminum busbars in energy distribution systems. The process is based on the extension of injection lap riveting to the connection of busbars made from the same material as the rivets and requires redesigning the joints to ensure complete filling with good mechanical interlocking and appropriate contact pressures on the overlapping area. The experimental work was carried out in unit cells and involved the fabrication of the riveted joints and the evaluation of their electrical resistance at different service temperatures. Comparisons with the bolted joints that were fabricated and tested for reference purposes show that injection riveted joints provide lower values of electrical resistance and require much less space for assembly due to the absence of material protrusions above and below their surfaces. Numerical simulation with finite elements allows the relating of the reduction in electrical resistance with the changes in the electric current flow when the bolts are replaced by the new type of rivets. The experimental and numerical predictions revealed that the new type of rivets experience an increase in electrical resistance of up to 6 μΩ (30%) when the service temperature approaches 105 °C. Still, the resistance at this temperature (26.2 μΩ) is more than 3 times smaller than that of the bolted joints (80.5 μΩ).

show abstract

“…Studies have shown that by reasonably adjusting and matching the thermal output of the VPPA, the requirements of welding assemblies in multiple fixed positions (e.g., horizontal welding, vertical-up welding, and flat welding) can be realized, which greatly broadens the application scope of this type of welding [ 11 , 12 , 13 , 15 , 16 ]. However, when the position is continuously changed during welding, gravity dynamically influences the keyhole weld pool and makes it difficult to maintain the quasi-stable state of fixed position welding, which becomes unstable during welding, and the metal melt behind the weld pool fluctuates greatly, which can cause intermittent closure or even a lack of closure, thus resulting in uneven weld morphologies and continuous cutting [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

Stability of Weld Pool and Elimination of Weld Defects in Aluminum Alloy Plasma Arc Keyhole Welding at Continuously Varying Positions

Wei

Zhang

et al. 2021

Materials

Self Cite

View full text Add to dashboard Cite

Mathematical statistics were used to study the stability of weld pool and the elimination of weld defects in aluminum alloy plasma arc keyhole welding at continuously varying positions. In the mathematical model, the mass transfer position and spatial welding position were taken as the input, and the shape of the welded joints (symmetry/deviation) was taken as the output. The results showed that the fitted curves of the front, back, and average deviations of the weld seam were all similar to the actual curves. According to the optimum results obtained in the experiment and the mathematical models, the mass transfer position only needs to be adjusted once (near to 30°) during the continuously varying positions, from vertical-up to horizontal welding. A breakthrough from fixed environmental variables to dynamic environmental variables in the process control of the keyhole weld pool was realized, which enabled the Al-alloy keyhole weld pool to resist the disturbance caused by gravity during variable position welding. The deviation of the welded joints of the whole plate was smaller than 0.5 mm, and the mechanical properties of the weld reached at least 85% compared to those of the base material, thus meeting the requirements of Al-alloy welding.

show abstract

Effect of Arc Pressure on the Digging Process in Variable Polarity Plasma Arc Welding of A5052P Aluminum Alloy

Cited by 17 publications

References 26 publications

Interaction Mechanism of Arc, Keyhole, and Weld Pool in Keyhole Plasma Arc Welding: A Review

Interaction Mechanism of Arc, Keyhole, and Weld Pool in Keyhole Plasma Arc Welding: A Review

Injection Lap Riveting of Aluminum Busbars—A Thermo-Electro-Mechanical Investigation

Stability of Weld Pool and Elimination of Weld Defects in Aluminum Alloy Plasma Arc Keyhole Welding at Continuously Varying Positions

Contact Info

Product

Resources

About