TY - JOUR

T1 - Influence of ultrasonic amplitude and position in the vibration distribution on the microstructure of a laser beam welded aluminum alloy

AU - Nothdurft, Sarah

AU - Ohrdes, Hendrik

AU - Twiefel, Jens

AU - Wallaschek, Jörg

AU - Mildebrath, Maximilian

AU - Maier, Hans Jürgen

AU - Hassel, Thomas

AU - Overmeyer, Ludger

AU - Kaierle, Stefan

N1 - Funding information: The results presented in this paper were obtained from the Collaborative Research Centre 1153 “Process chain to produce hybrid high performance components with Tailored Forming” in subproject A3. The authors would like to thank the German Research Foundation (DFG) for the financial and organizational support of this project.

PY - 2019/4/9

Y1 - 2019/4/9

N2 - There are many reasons for influencing the laser beam induced weld pool. The manipulation of the dynamics, the solidification, the resulting grain size, and in the end, as a result of the aforementioned influencing, the mechanical characteristics of the weld is the aim of different attempts to gain an impact on the melt. Aluminum alloys tend to porosity formation because of different solubility of hydrogen in solid and liquid states. For reliable welds, the porosity has to be limited. An ultrasound excitation is one possibility to allow a fast degassing, especially for the considered round bars, for which no welding through is possible for geometric reasons. The presented research shows the influence of the ultrasonic amplitude on the microstructure of laser beam welded round bars of the aluminum alloy AA6082-T6. Furthermore, the position of the weld pool in the vibration distribution is varied and the influence evaluated. Metallographic cross sections show in analyses the resulting weld characteristic and the microstructure of the weld metal. The grain size and the grain orientation are evaluated for the different ultrasound parameters. Additionally, the summed porosity area is compared to acquire knowledge about the correlation between ultrasound excitation (with regard to vibration amplitude and position in the vibration distribution) and pore formation.

AB - There are many reasons for influencing the laser beam induced weld pool. The manipulation of the dynamics, the solidification, the resulting grain size, and in the end, as a result of the aforementioned influencing, the mechanical characteristics of the weld is the aim of different attempts to gain an impact on the melt. Aluminum alloys tend to porosity formation because of different solubility of hydrogen in solid and liquid states. For reliable welds, the porosity has to be limited. An ultrasound excitation is one possibility to allow a fast degassing, especially for the considered round bars, for which no welding through is possible for geometric reasons. The presented research shows the influence of the ultrasonic amplitude on the microstructure of laser beam welded round bars of the aluminum alloy AA6082-T6. Furthermore, the position of the weld pool in the vibration distribution is varied and the influence evaluated. Metallographic cross sections show in analyses the resulting weld characteristic and the microstructure of the weld metal. The grain size and the grain orientation are evaluated for the different ultrasound parameters. Additionally, the summed porosity area is compared to acquire knowledge about the correlation between ultrasound excitation (with regard to vibration amplitude and position in the vibration distribution) and pore formation.

UR - http://www.scopus.com/inward/record.url?scp=85064216385&partnerID=8YFLogxK

U2 - 10.2351/1.5096100

DO - 10.2351/1.5096100

M3 - Article

AN - SCOPUS:85064216385

VL - 31

JO - Journal of laser applications

JF - Journal of laser applications

SN - 1042-346X

IS - 2

M1 - 022402

ER -