Numerical modeling and simulation for laser beam welding of ultrafine-grained aluminium

Laser beam welding of aluminium offers huge potential for a wide variety of welding of different thickness parts with the method of thermal conductivity due to the relatively high difference between melting temperature and evaporation. However, due to the high melting temperature and good thermal conductivity of this light metal, the temperature gradients during the welding process are usually high, causing residual stresses in the weld, which can lead to undesirable deterioration of the weld pool properties and the quality of the process. Physical modelling and simulations of the laser welding process are powerful tools for gaining a fundamental understanding of the technological process. They are also a suitable tool for preliminary assessment of the intervals in which the real preliminary experiments for process optimization should take place. This work is devoted to the numerical modelling of the process of welding ultrafine-grained aluminium using a fibre laser. A three-dimensional model of the welding process was created, using the finite element method implemented in the program ABAQUS. The temperature fields at depth <jats:italic>z</jats:italic> and on the surface <jats:italic>x, y</jats:italic> in the welded samples is determined. The temperature change as a function of time for different coordinates of the weld is also analysed. During numerical calculations, the power, machining speed and diameter of the workplace are variable. The obtained results are compared with real experiments conducted in the laboratory by other researchers.