Abstract <p>Using numerical modeling, the possibility of welding aluminum foam plates with an intermediate insert made of monolithic metal is assessed to obtain high-quality permanent connections. The height of the insert is greater than the thickness of the plates. A non-stationary mathematical model of welding under the influence of laser energy on the surface of a non-porous metal insert placed between the ends of the joined plates has been developed. The processes that determine the features of the resulting joints and seams for plates are considered. The material of the plates is foamed technical aluminum A0 with a thickness of 7 mm with an average porosity of 90%. The material of the monolithic insert is a similar alloy. To determine the initial and boundary conditions in the calculations, the conditions for experimental studies of welding plates with a CO₂ laser with a radiation power of 3 kW at scanning speed of 2 m/min and the resulting samples were used. It has been established that to obtain a weld of satisfactory quality, it is necessary to coordinate the thickness of the plates, their porosity, and the height of the insert and the power of the supplied energy. A feature of the welding process under consideration is the prolonged cooling and solidification of the molten metal, which is a consequence of the high porosity and low thermal conductivity of the plate material. The results of calculations and samples obtained during experimental studies are presented. The calculated characteristics of the joints of foamed aluminum plates are in satisfactory agreement with the results of physical experiments, which confirms the adequacy of the proposed model and contributes to the understanding of physical processes in the development of technology. The effectiveness of the considered plate welding method is confirmed by the results of tensile testing of the obtained samples.</p>