This title describes various eco-friendly joining techniques, which do not produce hazardous fumes or radiations. Structures are assembled together using various joining techniques. Traditional joining involves fusion technologies like welding, brazing and soldering, and foresees filler metal/electrodes to form the joint and flux to shield the weld zone and remove the impurities from the weld pool. The current research is progressing in the field of the joining of materials, through solid state techniques which do not involve melting and mostly do not need addition of filler metal or flux, do not emit toxic smoke, and result to be safer for workers, as well as for the environment.