What is Safety in welding?

Other solid-state processes include friction welding. This includes friction stir welding and spot welding. You have many options for how to make your welding joints. There are five basic types: the butt joints, lap joints corner joint corners joint edge joint and edge joints. The T-joint is a variation on the cruciform. There are many variations. Double-V preparation joint, for instance, is characterized by two pieces of material each tapering at a single center point at half their height. Common are single-U as well double-U preparations joints. These joints have curves, and instead of being straight like the double and single V preparation joints, but they form the shape and size of a U. It is not uncommon for lap joints to be more than two-pieces thick. However, depending on the process used and how thick the material, many pieces may be welded together in a lap join geometry.

Modern welding methods, unlike forge welding, do not require the melting of materials to be joined. Ultrasonic welding is one of the most well-known methods. It uses vibration to join thin metal sheets and wires. Although the equipment and methods are similar to resistance welding, vibration is used instead of an electric current to provide energy input. This process doesn't involve melting metals; instead, it uses mechanical vibrations horizontally under high pressure to form the weld. Plastics should have the same melting temperature as the metals and vibrations must be applied vertically when welding them. It is a common method for welding polymers.

Forge welding was a breakthrough in the Middle Ages. Blacksmiths used to repeatedly heat metal until it bonded. Vannoccio Biringuccio published De la pirotechnia in 1540. It includes detailed descriptions of the forging process. The process was mastered by Renaissance craftsmen, and the industry grew over the next centuries. Sir Humphry Davy, a British scientist, discovered the short-pulse electric arc in 1800. He presented his findings in 1801. The continuous electric arc was created by Vasily Petrov, a Russian scientist. He published his "News of Galvanic-Voltaic Experiments", which included details of experiments he had conducted in 1802. This work is notable for its description of stable arc discharges and indication of their potential use in many applications. Davy discovered the continuous electric arc in 1808 while unaware of Petrov's works. Stanislaw Olszewski (Polish), and Nikolai Benardos, a Russian inventor, created the first method of electric arc welding known as carbon arc welding. In the late 1800s, a Russian inventor, Nikolai Slavyanov (1888), as well as an American inventor, C. L. Coffin (1890), made metal electrodes possible. A. P. Strohmenger, a British inventor, released a coated metal electrode in 1900. This created a stable arc. Vladimir Mitkevich, a Russian scientist, suggested using a three phase electric arc to weld in 1905. C. J. Holslag invented alternating current welding in 1919. However, it didn't become very popular until a decade later.

Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had used for millennia to join iron and steel by heating and hammering. Arc welding and oxy-fuel welding were among the first processes to develop late in the century, and electric resistance welding followed soon after. Welding technology advanced quickly during the early 20th century as world wars drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding, now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. Developments continued with the invention of laser beam welding, electron beam welding, magnetic pulse welding, and friction stir welding in the latter half of the century. Today, as the science continues to advance, robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality.