“…(3) Using solid-state welding processes. Some studies consider friction welding, [65][66][67][68] friction stir welding, [58,[69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88] friction stir diffusion bonding, [89] ultrasonic welding, [90] roll bonding, [91][92][93] diffusion bonding, [64,75,[94][95][96][97][98] or hybrid processes [5] such as FSW assisted by diffusion bonding, [83] by an electrical current, [99] by gas tungsten arc welding, [100] or by a laser. [101] These solid-state welding processes require a significant heat input to ensure suitable steel plasticization or sufficient atomic mobility.…”