Pulsed Nd:YAG laser with maximal power 150 W is used in our laboratory to cut, drill and weld metal and non-metal thin materials to thickness 2 mm. Welding is realized by fixed processing head or movable fiber one with beam diameter 0,6 mm in focus plane. Welding of stainless and low-carbon steel was tested before and results are publicized and used in practice. Now the goal of our experiment was optimization of process parameters for aluminum that has other physical properties than steels, lower density, higher heat conductivity and surface reflexivity. Pure alumina specimen 0,8 mm and Al-Mg-Si alloy 0,5 mm prepared for butt welds. Problem with surface layer of Al₂O₃ was overcome by sanding and chemical cleaning with grinding paste. Critical parameters for good weld shape are specimen position from beam focus plane, pulse length and energy, pulse frequency and the motion velocity that determines percentage of pulse overlap. Argon as protective gas was used with speed 6 liters per second. Thermal distribution in material can be modeled by numerical simulation. Software tool SYSWELD makes possible to fit laser as surface heat source, define weld geometry, and make meshing of specimen to finite elements and compute heat conduction during process. Color isotherms, vectors, mechanical deformations and others results can be study in post-processing.

Date Published: 12 April 2007
PDF: 8 pages
Proc. SPIE 6609, 15th Czech-Polish-Slovak Conference on Wave and Quantum Aspects of Contemporary Optics, 66090O (12 April 2007); doi: 10.1117/12.739517

Published in SPIE Proceedings Vol. 6609:
15th Czech-Polish-Slovak Conference on Wave and Quantum Aspects of Contemporary Optics
Miroslav Miler; Dagmar Senderáková; Miroslav Hrabovský, Editor(s)