摘要
Aluminum specimens with and without chemically cleaning were welded by electron beam to investigate the effect of Al2O3 film on weld appearance. The removal mechanism of Al2O3 film during vacuum electron beam welding of aluminum was analyzed and the effect of Al2O3 film on molten pool flow behavior and weld appearance was investigated. The results showed that the weld width of the specimen was enlarged by chemically cleaning. The solid Al2O3 film transformed into gaseous Al2O3 via the reaction with liquid aluminum at the temperature higher than 1 350 K was the main reason for the removal of the film. The weld width was narrowed down by the oxide film due to the inhibition of outward flow driven by the surface tension gradient and the drag force between the Al2O3 film and liquid Al. The weld penetration was reduced in the initial stage and then enhanced in the metastable stage.
Aluminum specimens with and without chemically cleaning were welded by electron beam to investigate the effect of Al2O3 film on weld appearance. The removal mechanism of Al2O3 film during vacuum electron beam welding of aluminum was analyzed and the effect of Al2O3 film on molten pool flow behavior and weld appearance was investigated. The results showed that the weld width of the specimen was enlarged by chemically cleaning. The solid Al2O3 film transformed into gaseous Al2O3 via the reaction with liquid aluminum at the temperature higher than 1 350 K was the main reason for the removal of the film. The weld width was narrowed down by the oxide film due to the inhibition of outward flow driven by the surface tension gradient and the drag force between the Al2O3 film and liquid Al. The weld penetration was reduced in the initial stage and then enhanced in the metastable stage.
基金
supported by the International S&T Cooperation Program of China(Grant No.2011DFR60)
