Optimization of Process Parameters For Improved Mechanical Properties of Friction Stir Welded Joints of Aluminum Alloy

Abstract

The history of joining processes is supposed to become into existence in the Bronze newlineAge, as Gold circular boxes were recovered 2000 years ago. It was estimated that they newlineare made from pressure welding. Weapons and tools recovered from Egyptian newlinepyramids are supposed to be of 3000 years old. They are made of bronze and iron. It newlineexhibits that forge welding operations were used to make these items. The iron pillar newlineof Delhi, established 1700 years ago was also welded by hammering. newline19th century is known for the development of welding processes in a newlineprofessional way when acetylene was discovered by Sir Humphrey Davies. He was newlinesuccessful in a produced arc by using carbon electrodes connecting them with battery. newlineThe invention of the electric generator made popular arc lightning. Arc welding, gas newlinewelding and cutting were also invented in the early 1900s. This is the time when newlineresistance welding became popular. De Meritens successfully joined lead plates by the newlineapplication of heat of the arc. He did this experiment in France for storage battery in newline1881. The patent of welding was granted to Nikolai Benardos and Stanislaus newlineOlzewski in last 1800s. newlineCL Coffin granted the first US patent for the use of metal electrode for arc newlinewelding process in 1892. The invention of the coated metal electrode by Stromeyer in newlinethe 1900s added another feather to the development of welding processes. After this newlineinvention, Oskar kjellberg produced stick electrodes in 1907. The welding processes newlinecome under the category of resistance welding were also developed in this era such as newlinespot welding, projection welding, seam welding and flash welding. Thermite welding newlinewas invented by Goldschmidt in 1903. The Thermite welding initially was used to newlineweld rails. newlineIn the early1900s oxy-acetylene welding and cutting processes were used for newlinemaintenance work. As necessity is the mother of invention it was World War-I that newlinedemand the welding as a servicing process. It was the time when the US and Europe newlineproduced various types of welding machines and electrodes. American welding newline2 newlinesociety came into existence in the 1920s intending to advance welding and allied newlineprocesses. This was a non-profit organization made by 20 members of the Wartime newlineWelding Committee when war was over. General Electric Company was another newlinepioneer in developing welding processes as it introduced an automatic welding newlinemachine in 1920. Initially, it was used to make worn crane wheel. Later it was newlineadopted to produce rear axle housing by various automobile industries. In 1920 so newlinemany research works were conducted to develop electrodes of various grades. On the newlineone hand, copper alloy rods, alloy steel electrodes and high carbon electrodes were newlinestarted using during this era on the other hand gas shielded welding techniques were newlinedeveloped by researchers. In 1930 stud welding process became popular when it was newlineinvented in New York by Navy and it attracted so many construction and shipbuilding newlineindustries. newline