Artefacts (Idenitifying Materials)

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Quality assurance plays an active role in materials testing. Quality assurance carries out calibration test and manufacturing test. Calibration test is carried out to determine the workability of the measuring properties. Manufacturing test is carried out to determine the adherence to standardization. Some of the tests through which engineering materials are subjected to can be categorized as follows. Mechanical test These tests are carried out on the engineering materials to determine their strength, elastic constants, material properties and performance properties. Mechanical test involves testing the test specimen. The test specimen is obtained through the breaking of the original sample materials. Tensional test These are quasi-static test carried out on the engineering materials to determine the properties of these materials. This test is carried out by exposing the sample material to uniaxial loading conditions. Hardness test The resistances to penetration by most engineering materials are determined by hardness test. Hardness test is carried out using three different methods that are scratch test, rebound test, indentation test. Scratch test involves progressive scratching of a hard material. Rebound test involves the ability to determine the material resilience. Material resilience is determined by measuring the potential energy of the material. Indentation test involves production of a permanent impression on the surface of the materials. The size and the force of the impression determine the material hardness. Hardness test can further be categorized as macro hardness test or micro hardness test. The macro hardness test includes Brinell, Vickers and Rockwell tests. Micro hardness test includes Knoop and Tukon test. Torsion test This is a test that is carried out to obtain the stress-strain relationship for the metal. Torsion test is able to generate both the shear stress and shear strain of the material. Impact test This test is conducted to determine the static properties and the mechanical behavior of the engineering material. Heat treatment and the stress concentrations of the material are carried out under impact test. When the drill (Osaki CD 1202 12V) was stripped down, the following material components were identified. Polystyrene polymer Polystyrene is a vinyl polymer structurally made up of very long hydrocarbon chain. The polystyrene polymer has a phenyl group attached to its carbon atom. This polymer is hard and it is a clear plastic. Polystyrene is made from free radical vinyl polymerization of the monomer styrene. This polymer is hard and it is used for making of the drill handle. Due to its hard nature, it is able to withstand a lot of heat. Nylon This is a thermoplastic polymer which is used as a fiber. Nylons are made from diacid chlorides and the diamines.One of the nylon polymer that is nylon 6, 6 is produced from the combination of two monomers. The two monomers are adipoyl chloride and hexamethylene diamine. Another form of nylon is the nylon 6. Nylon 6 is made from a ring opening polymerization. These nylons are used in making the casing for the ball bearing. It is preferred because of its ability to be fabricated into any shape. Diamond This is the hardest engineering material. They are gem-quality carbon crystals. They are highly refractive crystalline carbon types and are used in abrasives, cutting tools and drilling operations. They have slight impurities in their structures, but they are