In this research, the authors aimed to manufacture and weld in-situ composite foam-filled tubes from expanded clay aggregate particles, AlSi12 aluminum matrix, and AlMgSi0.5 tubes using tungsten inert gas welding. Subsequently, the quality of the welded joints was examined after precipitation hardening heat treatment and without heat treatment, followed by the evaluation of the results. The welded joints were characterized by microstructural examinations, microhardness measurements, and hardness testing. It was found that the hardness of the tube can be increased with heat treatment after the welding by 23 % on average and that the heat input of the welding process causes silicon enrichment due to diffusion within the AlMgSi0.5 tube, which is accelerated by the heat treatment cycle.