Fundamental study of narrow-gap welding with oscillation laser beam

Abstract

Laser welding with oscillation laser beams enables control of the heat input distribution. In this study, we attempted to develop a narrow-gap welding process with oscillation laser welding. This process is expected to prevent a lack of fusion because the entire bottom to the groove can be melted by the oscillation laser. As the first step of the study, bead-on-plate welding experiments with an oscillation laser beam were performed to investigate the relationship between the welding conditions and welding results. The experiments revealed that the oscillation conditions strongly affect the welding penetration shape. It was clarified that the wire melting phenomena in oscillation laser welding differed from those of straight (nonoscillation) laser welding. Additionally, narrow-gap laser welding experiments were performed to investigate the relationship between the oscillation conditions and gap width. The results confirmed the effectiveness of oscillation laser welding for narrow-gap welding.

Experiment and prediction of weld morphology for laser oscillating welding of AA6061 aluminium alloy

“…As shown in Figures 9 and 10(b), the welding keeps keyhole mode at very high velocity when the D is less than the δ 0 of 2.8 mm, while it has a rapid transfer from keyhole mode to conduction mode with the increase of oscillating velocity when the D is larger than δ 0 . It is deduced that the η D is dependent on the δ 0 and D, and has an exponential relation with them, as shown in Equation (11).…”

“…Miyagi et al found that the serious spatter and surface voids of laser welded pure Cu could be suppressed by high-frequency circular beam oscillation [9]. Hao et al found that the morphologies of laser-welded stainless steel are varied with the frequency and amplitude of transversal beam oscillation, but Yamazaki et al pointed out that the spatter easily occurred at reversal points in transversal oscillation [10, 11]. Stefan suggested that welds are more uniform in shape as increasing the frequency in the laser transversally welding of structural steel [12].…”

Effects of Oscillation Width on Arc Characteristics and Droplet Transfer in Vertical Oscillation Arc Narrow-Gap P-GMAW of X80 Steel

“…Liu et al [18,19] placed a tungsten electrode arc after the triple-wire indirect arc for narrowgap welding, which led the weld bead surface to transform from a convex to a concave shape. An oscillation laser is also used in narrow-gap welding, and the influence of laser oscillation parameters on weld forming, the relationship between groove width and lack of fusion and the microstructure and mechanical properties of welded parts have also been studied by scholars [20][21][22][23]. At the same time, some researchers have studied laser-arc composite narrow-gap welding, revealing the influence of welding parameters, such as laser power, wire feeding speed and welding current, on droplet transition behavior in flatposition welding [24][25][26][27].…”

Effect of joint-extrusion-force on the plasticity of beam oscillation fiber laser welded X2CrTiNb18 ferritic corrosion resisting steels

“…In the laser welding process, the amplitude, frequency and power of the laser beam were adjusted, changing the size of the weld pool, reducing the number of spatters, and stabilizing the welding process [4][5][6]. For example, Yosuke Yamazaki et al found that as the amplitude became greater, the weld surface was wider, and the weld depth was shallower [7]. With the increasing of the oscillation frequency, the difference in the width of the top and the bottom reduced in the weld cross section.…”