Brazing and soldering require the application of a number of scientific and engineering skills to produce joints of satisfactory quality and reliability. Brazing employs higher temperatures than soldering, but the fundamental concepts are similar, particularly with respect to metallurgy and surface chemistry. Brazing and soldering are joining processes performed at temperatures below the base material solidus temperature. To fill the joint, the liquid filler metal must spread through the joint gap by capillarity or coat the substrate by spreading.
