Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode are protected from oxidation or other atmospheric contamination by an inert shielding gas (argon or helium). A filler metal is normally used, though some welds, known as autogenous welds, or fusion welds do not require it. When helium is used, this is known as heliarc welding. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma. GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process grants the operator greater control over the weld than competing processes such as shielded metal arc welding and gas metal arc welding, allowing for stronger, higher quality welds. However, GTAW is comparatively more complex and difficult to master, and furthermore, it is significantly slower than most other welding techniques. A related process, plasma arc welding, uses a slightly different welding torch to create a more focused welding arc and as a result is often automated.
Wolverhampton (/ˌwʊlvərˈhæmptən/ (About this soundlisten)) is a city, metropolitan borough, and administrative centre in the West Midlands, England. At the 2011 census, it had a population of 249,470. Natives of the city are called "Wulfrunians".
Historically part of Staffordshire, the city grew initially as a market town specialising in the wool trade. In the Industrial Revolution, it became a major centre for coal mining, steel production, lock making, and the manufacture of cars and motorcycles. The economy of the city is still based on engineering, including a large aerospace industry, as well as the service sector.