Article ID Journal Published Year Pages File Type
1690892 Vacuum 2011 7 Pages PDF
Abstract

Seen from gas-liquid two-phase-flow system, the gas phase and liquid phase of bubble flow in weld pool are studied by means of isolated phase based on the conservation of mass and momentum. The two-dimensional fractional flow model of bubble flow in weld pool of vacuum electron beam welding is developed. And the gas distribution and the phenomenon of bubble flow in weld pool of AZ91D magnesium alloy are simulated to analyze the formation and distribution of cavity defects. The results show that the possibility of gas escape in fully penetrated weld pool is much greater than non-penetrated weld. It appears that the probability of cavity defects is lower than non-penetrated weld to some extent. The formation of typical cavity defects is closely related to the flow pattern and flow characteristics of the bubble flow in deep penetration weld pool of vacuum electron beam welding. Higher liquid flow rate is more conducive to the escape of gas in molten metal, so that the final porosity in weld is low.

► The paper stated a two-dimensional fractional flow model of bubble flow in weld pool of vacuum electron beam welding. ► The gas distribution and the phenomenon of bubble flow in weld pool of AZ91D magnesium alloy are simulated to analyze the formation and distribution of cavity defects. ► The results are conducive to the cavity defects mechanism study and the welding process design.

Related Topics
Physical Sciences and Engineering Materials Science Surfaces, Coatings and Films
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