The 12th TIMA21 which was held in Timi oara, Romania, by videoconference (November 25-26, 2021), paid particular attention to practical problems in the area of new joining technologies, mechanical and structural characterization of advanced materials and joints, corrosion and assessment of damage state. The volume includes selected papers in which the authors reveal the results of their own research and development activity, carried out in the frame of their institutes, universities and economic field from Romania, Hungary, Serbia, Ukraine, Bulgaria, and Latvia.