Mechanical Testing - Lab Report Example

? Mechanical testing Lab report Introduction. Tension test is considered to be a basic category of mechanical test that can be permed on a material. Such a test is proven to be inexpensive, simple, and extremely standardized. Through pulling on something one will quickly be able to find out how a material can react to different forces that are applied to the tension. When the material is pulled, one would be able to establish the strength of the material. In this regard, tensile testing can help one to develop an insight into various substances. Whenever one continues to pull on a material, the material will break hence one would get a recommendable profile of tensile. In this case, a curve will display the manner in which the material reacted towards the forces being applied to it. More often than not, a point of failure is established in a material. This point is referred to as the Ultimate Strength (UTS). Considering Hooke’s law, tensile testing, one will realize that in the initial part of the test the link between the force applied and the specimen’s elongation will be linear. For the region that is linear, the Hooke’s law will be obeyed by the line and the stress to strain ration will be a constant (E= ?/?) (Bagramov, 2007). In this relation, E is the line’s slope, ? represents the strain proportion, and ? is the Young’s Modulus or the elasticity Modulus. The strain and stress levels of a material will also be determined. Stress is the measurement that is absolute in length change. It is the ration of the length change to length that was original. This is given by L-L0/L0. On the other hand, strain is considered to be the strain in the resistance that is internal of a material to the effects of an external force that are distorting. The forces that are countering appear to return atoms to the positions that are normal. This means that the total developed resistance is equal to the load that is external. The resistance is said to be stress. Young’s Modulus involves the stiffness measurement and only applies to the region that is linear (Bonjour, 2008). When the curve stops to be linear and makes a deviation from the straight like Hooke’s law fails to apply and a condition known as permanent deformation will occur. Such a point is referred to as the proportional or elastic limit. In a tensile test, after the elastic limit, a material will reacts plastically towards the increment in the stress or load. Procedure. The Zwick Z010 Universal machine for mechanical testing was se up using the EAT104 2012.zpv program. The notes on the manner in which the test was done was recorded. The appropriate test conditions included a test speed of 6mm/min, test temperature of 21oC, Load cell of 10kN, a wedge grips, and a long travel extensometer approximately 50mm. The Glass filled test of Nylon was secured symmetrically, and centrally between the grips. The program was started, and the test stop at the instant sample fracture. The second and he third steps were repeated for the unreinforced material of nylon. There was no need to advance the test over the strain in which the composite sample did fail. In this case, the fail may occur at a 5% strain. In this case, the tensile test may be stopped at a similar strain value. Data was collected in terms of tensile stress against tensile strain. Results. The data collected was recorded in a table 1. Table 1. Stress Strain X Stress Strain N/mm? N mm N mm 72.46 1451.37 5.8 145 12.6 464.03 9294.36 2.9 3100 4.1 418.88 8390.03 6.9 2060 10.2 363.02 7271.18 1.2 1020 4.0 Discussion. The graph is a representation of Hooke’s law. According to this law the extension is directly proportional to the applied force unless the elastic limit is exceeded (Blatt 2004). It is evidenced from the graph that after exceeding the elastic limit, a permanent deformation is observed. In this case, the extension of the material fails to be directly proportional to the load applied. The hardness and tensile strength of a material indicate the resistance of a material towards plastic deformation. This study used materials that are relatively simple in terms of the nominal chemical makeup of the material. A microscope scans of the atomic force on polished file cross-section provides an interesting overview on the microstructure of the different material. The particles that are bright especially with sizes below 2um could be considered cementile carbides. This is due to their increased hardness (Barnard, 2005). After being polished, they tend to remain higher than the surrounding matrix that brings about their differentiation. The analysis of the image reports that some carbides occupy approximately 12% of the entire volume (Bonjour, 2008). Other matrix traits are discernible in the topography of images. When the applied stress is sufficiently low, a material may plastically not deform. This means that the material response will be a deformation that could be recovered completely upon the production of the stress applied, made up of anelastic and elastic part. Conclusion It is true to say that elastic deformation occurs to enhance full recoverability (Bagramov, 2007). This satisfies the need for being a linear proportion towards the stress applied and is instantaneous. The part considered an elastic is normally lower in the magnitude and is different from the part that is elastic in the manner in which the response of equilibrium is obtained after a substantial amount of time. In this respect, an elastic response is linked to the defect motion in the results and material in energy dissipation. The objectives set for this experiment were achieved References. Bagramov, R., 2007. Internal Friction in a Martensitic High Carbon Steel, Philosophical Magazine A81, 2797. Barnard, R., 2005. Thermoelectricity in Alloys and Metals. London: Taylor & Francis Ltd. Benkirat, D., 2007. Effects of Precipitation of the Thermo-electric Power of Iron-Carbon alloys, Acta Metallurgica 36, 613. Benoit, W., 2001. Dislocation: Description and Dynamics in Mechanical Spectroscopy Q-1: With Applications to Materials Science. Switzerland Uetikon-Zuerich,. Blatt, F.J.,2004. Magnon-Drag Thermopower in Iron, Physical Review Letters18, 188, 395. Blatt, F.J., 2009. Thermoelectric Power of Metals. New York: Plenum Press. Bonjour, C., 2008. Effect of Substitutional Impurities on the Low-Temperature Internal- Friction Spectrum of Cold worked Diluted Gold-Alloys, Acta Metallurgica 27, 1755. Read More