Study On Ultrasonic-tig Welding Process Performance Of Different Aluminum Alloys And Thin-walled Aluminum Tubes

In early times our group has established a system which had got a good weldingresult. The experiment results have showed that the Ultrasonic-TIG welding could notonly improve the quality of aluminum alloys weld, but also improve the weldingproductivity, which is an improving method of welding. In order to the further explorerof the role of ultrasound, This paper use Ultrasonic-TIG welding method to weld LD10、LF6and ZL114A three kind of aluminum alloys, and analysis the difference betweendifferent aluminum alloys under the impact of ultrasound. Derivation how the ultrasoniccavitation bubbles moved in ultrasound environment, analysis the affection of gas holein the weld under the ultrasound, and preliminary exploration that the mechanism ofultrasonic cavitation degassing was conducted. And in the last Applied theUltrasonic-TIG welding to the thin-walled aluminum tube welding process, discussingthe microstructures and performances of the small-diameter and thin-walled aluminumtube which was use U-TIG method to weld.Use Ultrasonic-TIG welding method to weld LD10、LF6and ZL114A three kind ofrepresentative aluminum alloys, explore the microstructure and performances’difference of Each material between U-TIG welded joints and general TIG weldedjoints. The result shows that: with the adding of ultrasound, the depth of the jointincreased while the width reduced, the grains in weld are significantly refined whichlead to a result that mechanical properties Improved. And in the same time thedistribution of The second phase has been changed. During the weld process, differentaluminum alloys appeared different problems: since Mg is weak in electron emitting, sothe arc was easily be interrupted in welding; ZL114A always have a good fluidity whichis due to it contains much Si. As a result, in weld process, the aluminum melt firstflowed to the bottom, cooled down and solidificated, and stratification occurred in theweld; And the LD10and ZL114A is sensitive to hydrogen gas hole. All Thesephenomena significantly improved with the adding of ultrasound.The gas hole is most likely to occur when welding aluminum alloys. This paperanalyzed the affection of gas hole in the weld under the ultrasound. It can be seen by the experimental results that after adding the ultrasound, the number of the gas hole in theweld were significantly decreased. And in the same time, preliminary exploration thatthe mechanism of ultrasonic cavitation degassing was conducted: in the ultrasonicenvironment, cavitation bubbles occurred in the molten metal, the bubble constantlyoscillated even collapse because of the ultrasonic cavitation, and in the last, the bubblegot together then escaped to the atmosphere.Use the researches above to discussing the microstructures and performances of thesmall-diameter and thin-walled aluminum tube which was use U-TIG method to weld,and the results showed that: the U-TIG weld joint was more beautiful and the grains inU-TIG weld were significantly refined which lead to a result that mechanical propertiesImproved from150MPa to170MPa,which had increased about15%.