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Plasma-Metal Inert Gas (MIG) hybrid welding was employed to carry out bead on plate welding of an aluminum alloy A5052. The plasma arc was ignited to form a keyhole, and a series of welding systems were developed starting with MIG welding. The convective patterns within the weld pool were meticulously analyzed. In addition, we conducted experimental observations of the flow inside and on the surface of the pool, and we were able to visualize the flow in some areas. The results indicated that the plasma welding side formed a pool that seamlessly integrated the plasma side and the MIG side. At the same time, we observed the formation of a flow pool that integrates both plasma and MIG sides, affecting the formation and behavior of the weld pool. This study aims to provide a nuanced understanding of flow dynamics across the entire pool. This approach is geared towards refining the intricacies of weld pool dynamics for the advancement of welding technologies.

A hybrid welding technique formed by combining keyhole plasma arc welding (KPAW) and pulsed gas metal arc welding (GMAW-P) is characterized by the complex interactions of the arc, droplet, keyhole, and weld pool. With the help of a high-speed video camera, zirconia particles, and a thermal camera, the complex interactive phenomena of the hybrid KPAW-GMAW-P process was analyzed. Owing to the formation of a direct-current path between the KPAW cathode (tungsten electrode) and the GMAW anode (welding wire), the ionized plasma arc was extended to the GMA side, causing an expansion of the GMA. The current at the GMAW droplet was diverged; thus, the Lorentz force promoted a more stable one pulse one droplet metal transfer mode compared with that of GMAW-P. The strong backward flow from the keyhole was suppressed because of the pullpush flow pattern on the top surface of the weld pool between the two arcs. As the heat and molten metal in the weld pool were transported from the region near the GMA (high temperature) to the region near the plasma arc (low temperature), the weld pool temperature decreased. [ABSTRACT FROM AUTHOR]

In this paper we first introduce the concept of probabilistic interval space. Under this framework, a new version of KKM theorem is obtained. As application, we utilize this result to study some new minimax theorem, section theorem, matching theorem, coincidence theorem and fixed point theorem in probabilistic metric spaces. The results presented in this paper not only contain the main result of von Neumann[7] as its special case but also extend the corresponding results of [1, 3, 4, 6, 8] to the case of probabilistic metric spaces.