National University of Science and Technology MISIS, Moscow, Russia

N. V. Letyagin, Lead Research Project Engineer at the Department of Metal Forming, e-mail: n.v.letyagin@gmail.com
T. K. Akopyan, Senior Researcher at the Department of Metal Forming

Vladimir State University named after Alexander and Nikolay Stoletovs, Vladimir, Russia
A. V. Zavitkov, Postgraduate Student at the Department of Heat Engines and Power Plants
A. B. Lyukhter, Associate Professor at the Department of Heat Engines and Power Plants, Director of the Research & Education Centre for the Introduction of Laser Technologies

There is a growing interest to laser welding — a technique that combines versatility, localized heat and high welding speed, resulting in joints with a relatively high quality and a lower number of defects. Therefore, optimization of laser welding parameters is required, as well as further research into the effect of laser processing on the quality, structure and properties of materials. The aim of this research is to understand the applicability of the laser welding technique for joining together hot-rolled sheets of Al – 3 Ca – 0.5 Cu – 0.5 Mn alloy. The authors analyzed the structure and properties of a model Al – 3 Ca – 0.5 Cu – 0.5 Mn alloy. It is shown that this composition contributes to the formation of a fine eutectic structure during casting, favorable for rolling processes. Sheets that were hot rolled at 400 оС (80% reduction rate) have a tensile strength of 227 MPa, a yield strength of 176 MPa, and an elongation of 3.8%. The obtained sheets were joined together using a robotic laser welding unit. The results of structural and mechanical studies were used to analyze the influence of the test welding parameters on the welding quality. Optimum welding parameters were selected, which are as follows: laser power — 1,200 W, welding speed — 20 mm/sec, focal length — 193 mm, argon flow rate supplied to the welding zone — 15 l/min. Application of the above welding parameters result in welded joints of high visual quality, with minimum porosity in the fusion zone, as well as a good combination of mechanical characteristics. The obtained joints have a tensile strength of 171 MPa, a yield strength of 94 MPa, and an elongation of 3.2%.
Support for this research was provided under Grant No. 22-79-00179 by the Russian Science Foundation, https://rscf.ru/project/22-79-00179/.

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