IntroductionThere are different methods of joining two or more metal (or thermoplastic) parts, among which welding is the most studied and used in the industry. Welding is performed by joining two separate pieces of material by raising the working temperature high enough to cause softening or melting, thereby achieving coalescence. Filler material is usually added to parts during fusion to strengthen the joint. [1] The filler material is deposited from a special electrode connected to the electrical circuit which also includes the work pieces. [2]The number of different welding processes has increased in recent decades. These processes differ greatly in how heat and pressure (when used) are applied, as well as the type of equipment used. [1] A simple and logical way to classify welding processes is based on the energy sources used to achieve coalescence. Welding processes can be broadly classified as follows: (1) thermochemical welding; (2) pressure welding; and (3) fusion welding. [3]Thermochemical and pressure welding...