| Recently, Titanium alloy structure welded by EBW is employed in military armament. However, it is found that sometimes the property of high thickness welded component is unstable. According to experience, weld shape affect welded joint property. Therefore, it is necessary to study factors resulting in the weld shape varying. Furthermore, research on some method, which is proper to change weld shape, and improve property of welded joint, is also necessary.In this paper, two experimental tasks were investigated for TC4 titanium alloy. On the one hand,weld shapes by different EBW parameters were investigated in order to find the effect of EBW parameters on weld shape. On the other hand, the characteristics and merits of EB scanning welding were investigated through EBW test, EB defocused welding test and EB scanning welding test.It was found that focus current has a large influence on weld shape. Changing focus current leads to great change of weld shape. The effect of welding speed on weld shape is less important than that of focus current,there are no much greater change present in weld shape as changing welding speed.Beam current has little influence on weld shape,with various beam current the change of weld shape approximate integral reducing and enlarging.At the same time, compare to EBW, two important effects brought by EB scanning welding. Firstly, EB scanning welding changed weld shape effectively. Secondly, EB scanning welding improved microhardness of weld zone. Compare to EB defocused welding, no obvious distinction being found. Especially,it is much more difficult to differentiate each other's weld shape and mechanical property. |
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