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7 Keyhole and Weld Pool Dynamics in Dual-Beam Laser Welding
Fig. 7.16 Oscillation curves
of keyhole depth within
30–35 ms in parallel dual
beam welding with different
spot spacing
Beam spot spacing = 0.25 mm
Beam spot spacing = 0.5 mm
Beam spot spacing = 1.0 mm
Keyhole depth/mm
Time t/ms
reaches the stable oscillation stage, the oscillation takes on a certain periodicity.
When the beam spot spacing is 0.25 mm, 0.5 mm and 1.0 mm respectively, the
number of keyhole oscillation within 30 ms is 5–8 times, which indicates that in
parallel dual beam laser welding, the frequency of keyhole depth oscillation can
reach thousands of Hertz, on the same order of magnitude as single laser welding.
7.4.2.5 Influence of Welding Speed on Characteristics of Keyhole
Depth Oscillation
Figure 7.17 is a statistical graph showing the number of keyhole oscillations with
the amplitude larger than 0.15 mm at different welding speeds within 35–40 ms.
Figure 7.18 shows how the maximum amplitude of the keyhole varies with the
Fig. 7.17 Number of
keyhole oscillations with the
amplitude larger than
0.15 mm at different welding
speeds within 35–40 ms
Number
n
Welding speed v /(m·min
-1 )