A Novel Method of Supporting the Laser Welding Process with Mechanical Acoustic Vibrations

Abstract

The research described in this article presents a new contactless method of introducing mechanical vibrations into the base material during CO2 laser welding of low-carbon steel. The experimental procedure boiled down to subjecting a P235GH steel pipe with a 60 mm diameter, 3.2 mm wall thickness and 500 mm length to acoustic signals with a resonant frequency during the welding process. Acoustic vibrations with a frequency of 1385, 110 and 50 Hz were introduced into the pipe along the axis and transversely from the outer surface. The obtained welds were then subjected to structural tests and Vickers hardness measurements. The results of comparative tests show the impact of such introduced vibrations on the granular structure of the welds, as well as on their microhardness in specific areas, such as the face, penetration depth and the heat-affected zone. The effectiveness of the proposed method of introducing vibrations in the scope of grain size and shape as well as changes in the hardness distribution in the obtained welds is demonstrated.

Support with mechanical vibrations of welding processes review of own research

“…It is also worth dealing with the aspect of precise determination of vibration parameters and methods of their introduction so as to become independent of the variable distance of the welding heat source from the vibration source. In the near future, special emphasis will be placed on the research being a continuation of the work [16,19], while in the long term it is planned to support the coating application processes with mechanical vibrations.…”

“…Research related to the application of mechanical vibrations during welding processes shows that it is possible to achieve satisfactory results without the need to directly and securely attach the vibrating system to the base material. Vibrations can be introduced, for example, by means of pulses of a laser beam [18], controlled electric arc modulation [16] or impact methods using the transfer of mass collision energy [19]. One of such methods is described in [19].…”

“…Vibrations can be introduced, for example, by means of pulses of a laser beam [18], controlled electric arc modulation [16] or impact methods using the transfer of mass collision energy [19]. One of such methods is described in [19]. It is interesting because the vibrations are introduced acoustically, i.e.…”

“…The presented results of laser remelting with the participation of acoustic vibrations show that they can affect both the geometry of the weld and the microstructure. The scale of these changes is small with the effects obtained by other methods that directly introduce vibrations [4,15,20], but it makes it possible to achieve constant conditions at the welding site using non-contact vibrations transmitted only in gas, as is the case in [19]. It is worth mentioning that the maximum depth of penetration and, at the same time, the minimum width of the face were obtained in the case of a weld subjected to 50 Hz vibrations propagating axially inside the pipe (remelting No.…”

Laser Irradiation for Enhancing Mass Transfer in the Solid Phase of Metallic Materials

“…The application of such methods of combined laser processin effect on a metallic surface of the thermal power of a laser beam a or acoustic vibrations, is promising in the development of laser te combined treatment by means of dosed introduction of mechan base material, it is also possible to control the hydrodynamic mot laser welding process is carried out with mechanical acoustic vib which an additional effect is exerted on the surface of the material to an improvement in the granular structure of the welds, as we hardness in specific areas of the heat-affected zone [93,94]. There i of diffusion processes and phase transformations, which has a po turally stressed state of the treated material.…”