Analysis Of Defect And Disincentives Inquiry On The Cross-weld Between FSW And VPPAW Of2219Aluminum Alloy

In today’s industry production, due to the characteristics of low density, highspecific strength, good cutting performance, excellent mechanical performance, thealuminum alloy has become one of the more and more used metal in many industries,especially in the aerospace, weapons and automobile manufacturing industry.However, in the light of the aluminum alloy welding, the defects such as pores andcracks always appear when we take the traditional welding process, and the inventionof the Variable Polarity Plasma Arc Welding (VPPAW) and Friction Stir Welding(FSW) remedy the defect excellently. VPPAW and FSW are two most excellentwelding methods now, and they have become the indispensable welding methods tothe aluminum alloy due to their excellent welding performance, beautiful appearanceof weld and good maneuverability.The VPPAW and the FSW have no problems when they take the work ofaluminum alloy welding separately. But the cross weld will be inevitable when weweld the complicated structures such as external tank of space shuttle, and then thestand or fall of the cross weld will directly affect the quality of the welding joint.In this paper, we take the2219aluminum alloy as the study materials, throughthe use of experiments such as the heat treat to the weld of FSW to simulation ofthermal-cycle, taking the bead weld of VPPAW to the weld of FSW by the paralleldirection and the cross weld between VPPAW and FSW, we found that the maindefect of cross weld between VPPAW and FSW is the pore defect along thedistribution of the welding fusion line of VPPAW, and the strict surface cleaning andgood welding process are also play a very important role in the form of the cross welddefect. According to the formation analysis of the defect, we raise several controlmeasures including removing the anastomosis area by the method of mechanicalprocessing such as milling and double-sided FSW, strict surface cleaning and give thereasonable welding process window by the use of strict orthogonal test, and achievethe expected effect of defects inhibit.