Joining and Fastening Processes (Manufacturing Engineering Processes) - Term Paper Example

These engineering materials in their raw form are extracted from their ores. These raw materials from ores are transformed into molten form through refining and reducing processes. The molten material is process through molds to produce commercial or industrial castings called ingots. These ingots are then processed through rolling to transform these into billets, rods and slabs suitable for marketing. These materials then undergo various manufacturing processes to obtain useful products in diverse range of sizes, shapes and forms desired by end user.

According to Singh, these manufacturing processes are classified into six major categories: primary shaping processes, secondary shaping processes, metal forming processes, joining and fastening processes, surface finishing processes and processes to change characteristics and properties of materials (17). In this report, we would be focusing on joining and fastening processes required to assemble or join different parts of a product. The process where two or more parts of the product are put together to achieve desired shape and function is called assembly, not to be confused with joining and fastening processes.

In joining, different parts of the product are joined together to obtained desired function. . A unique advantage of this process is the focus of heat in welding area ensuring less spread of heat thus reducing welding defect like warping and buckling. In addition, this concentration of heat increases the depth of welding and increases the welding speed of the process. Arc welding process consists of a heat source, shielding and a filler metal. The heat is produced through the electrical arcing between the two metals under contact (Zeilke 4).

The power source is referred to as welding machine which may be electrical or mechanical. Shielding gas, fluxes or coatings are used to prevent the welding area from surroundings during the welding process. Generally, arc welding is divided into ten main types called Carbon Arc Welding, Submerged Arc Welding, Stud Arc Welding, Gas Metal Arc Welding, Electro-slag Welding, Plasma Arc Welding, Shielded Metal Arc Welding, Atomic Hydrogen Welding, Gas Tungsten Arc Welding and Electro-gas Welding. In Carbon Arc Welding, a pure graphite rod is used as non-consumable electrode to generate arc for producing heat.

The welding can be made without or with introduction of filler metal. It can be further classified as single or twin carbon electrode welding. In Shielded Metal Arc Welding, a flux coated electrode is used to produce arc where the flux on the coated electrode fads off due to heat. In Submerged Arc Welding Process, a bare electrode is used as consumable electrode with flux feeder tube. The arc, electrode and molten pool remain submerged under granular flux to achieve homogenous welding across the structure.

In Tungsten Arc Welding, a tungsten electrode as non-consumable electrode covered by shielding of an inert gas to prevent these from surroundings is used for welding.