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Aluminum-Manufacturing Methods
Published in Raghu Echempati, Primer on Automotive Lightweighting Technologies, 2021
Extrusions can be joined a number of ways. Many different welding techniques can be employed as well as other creative solutions. The types of welding can include metal inert gas (MIG), tungsten inert gas (TIG), laser, spot, and friction stir welding. Some of the other common joining technologies include blind rivets, self-piercing rivets, compression fit joint, clinching, bolting, and adhesive bonding. There are many advantages by joining several smaller extrusions to a larger part including: Easier part handlingPressing, surface treatment, and machining which can be done on a more rational basisSmaller extrusions which can be produced with less material thickness, better accuracy, and lower die costs
Soldering, brazing, and welding
Published in Andrew Livesey, Motorcycle Engineering, 2021
Brazing is used extensively throughout the frame building trade as a quick and cheap means of joining frame tubes and other components. Although a brazed joint is not as strong as a fusion weld, it has many advantages that make it useful for the frame builder. Brazing is not classed as a fusion process, and therefore cannot be called welding, because the parent metals are not melted to form the joint, but rely on a filler material of a different metal of low melting point, which is drawn through the joint. The parent metals can be similar or dissimilar as long as the alloy rod has a lower melting point than either of them. The most commonly used alloy is of copper and zinc, which is, of course, brass. Brazing is accomplished by heating the pieces to be joined to a temperature higher than the melting point of the brazing alloy (brass). With the aid of flux, the melted alloy flows between the parts to be joined due to capillary attraction and actually diffuses into the surface of the metal, so that a strong joint is produced when the alloy cools. Brazing, or hard soldering to give it its proper name, is in fact part fusion and is classed as a skin fusion process.
Tungsten Inert Gas Welding
Published in P. Chakravarthy, M. Agilan, N. Neethu, Flux Bounded Tungsten Inert Gas Welding Process, 2019
P. Chakravarthy, M. Agilan, N. Neethu
The major safety requirements in TIG welding are proper insulation of power cables, ensuring safe fixing of return clamps and safety against welding fumes and arc radiations. The high-frequency spark used to initiate the arc can occur through any break in the insulation and can cause deep burns which can be very painful. The delivery of inert gases such as argon and helium into confined spaces may lead to the oxygen content of the air being reduced to a point where there is a danger of asphyxiation. Enough ventilation during welding is essential to avoid this situation. Advanced in-situ fume extraction hoods are available to remove toxic fumes generated during welding. For safe practice, the welder should be equipped with personal protective equipment such as welding helmet with appropriate shade, suitable respiratory mask, flexible welding gloves, apron and welding goggles.
TIG welding parameters optimization of Al–Si–Mg ternary alloy–SiC powder reinforced composites using Taguchi and RSM techniques
Published in Cogent Engineering, 2022
Jayashree P. K., Sathyashankara Sharma, Nagaraja Shetty
The most common fusion welding practices are TIG and MIG welding. Except for tungsten inert gas (TIG) welding and metal inert gas (MIG) welding, all other conventional welding has been found ineffective (Chen et al., 2002). TIG welding is a high-quality weld that uses a non-consumable electrode. The current utilized in TIG welding is smaller than in MIG and it may or may not be used with a filler wire. Fusion welding methods usually result in defects like porosity, oxide formation and hot cracking. These defects are an outcome of various reasons during the process. Entrapment and dissolution of the gases in the weld zone during solidification leads to porosity that has been overcome by the TIG welding process which has less hydrogen gas contamination of the filler wire during melting. Using alternate current during the TIG welding process with appropriate shielding gas reduces the oxide formation, hence oxide inclusion in the weld metal. The hot cracking defect is reduced by using a filler metal possessing a melting point nearer to that of base metal. Above all, important parameters like the welding current, welding speed and gas flow rate are to be considered along with proper weld preparation and joint design (Jahangiri et al., 2013; Mathers, 2002). The chemical reaction is one key issue in most of the fusion welding processes for MMCs. This is due to the long contact period between a molten metal matrix and particulate reinforcement that leads to adverse chemical reactions. The liquid aluminium will react with SiC reinforcement to precipitate aluminium carbide (Al4C3) and also intensify the silicon content upon cooling down the molten metal matrix, according to the interface reaction (Urena et al., 2000).
Compositional variations in metal nanoparticle components of welding fumes impact lung epithelial cell toxicity
Published in Journal of Toxicology and Environmental Health, Part A, 2023
Li Xia, Jae Hong Park, Katelyn Biggs, Chang Geun Lee, Li Liao, Jonathan H. Shannahan
Welding is a joining process that produces the coalescence of materials by heating them to the welding temperature with or without pressure and addition of filler material. To heat metals, various heat sources including electric current (arc), friction, ultrasonic, explosion, and gas pressure have been used in industry. Among all types, arc welding is the most extensively utilized to join metal parts by fusion (Kah et al. 2014). Four types of arc welding, including shielded metal arc welding (SMAW; also called stick welding), gas metal arc welding (GMAW), flux-cored arc welding (FCAW), and gas tungsten arc welding (GTAW) are widely employed (Antonini 2003).
Occupational survey of airborne metal exposures to welders, metalworkers, and bystanders in small fabrication shops
Published in Journal of Occupational and Environmental Hygiene, 2019
Allison L. Insley, Joshua R. Maskrey, Laura A. Hallett, Rachel C.D. Reid, Erin S. Hynds, Christopher Winter, Julie M. Panko
Welding is a general term that encompasses a wide variety of metal joining techniques that involve melting a consumable metal and/or base metal using a high energy source. Commonly used welding techniques include: shielded metal arc welding (SMAW, also known as stick welding or manual metal arc welding (MMA)); gas metal arc welding (GMAW, also known as metal inert gas (MIG) welding); gas tungsten arc welding (GTAW, also known as tungsten inert gas welding (TIG)); flux-cored arc welding (FCAW); submerged arc welding (SAW); and plasma arc welding (PAW).[3,4]