Aluminum, Aluminum Alloys, and Metallic Matrix Composites - Assignment Example

INDIVIDUAL DESIGN REPORT Name: Instructor: Institution: City: Date: 1. After the various experiments, our group established that the material used to make the component was an alloy of, Aluminum, 6061, T6. The conclusion was arrived at after conducting all of our tests on the seat post samples and doing all of the calculations and graphing of suitable tests to determine the most important factors of the material make up. Using the most important factors such as the density, yield strength, uniform elongation, the tensile strength and the range of hardness (HV) we found as well as the spectroscopy makeup of the material. The final step involved using the known values obtained from the calculations and graphs alongside the CES level 3 to determine the material. 2. The tensile test to obtain data for calculating tensile strength, ultimate tensile strength, Young’s modulus, uniform elongation and total elongation was the perfectly done experiment. Most of the group members seemed familiar with both the equipment and the procedure and as a result, the experiment was smoothly done to completion. The group did not carry out the Spectroscopy test since the Deakin laboratory does not have the proper machine or equipment to do the test. As a result, the results used in the experiment were given by the lecturer. Hence, given another chance, most of the team members would like to practically carry out the Spectroscopy test and observe what happens. 3. Each member of the group had a specific task to undertake during the experiment as well as in the recording, analysis and interpretation of the results. I was assigned the task of setting up the equipment and apparatus for the Tensile strength experiment as well as calculating the value of the young modulus from the experimental figures obtained. Another member of the group helped to develop the graphical representations using excel. A third member of the group was also assigned the role of setting up the experiment for Hardness test. Similarly, another group member was also responsible for compiling all the data, calculations and interpretations into a complete document for the group. Nevertheless, the group collectively discussed the results as well as the data obtained in which every member was allowed to give a personal contribution. 4. Young’s Modulus = 5. The seat post provides the sitting position to the rider. As a result, the material used to make the seat post must have a high tensile strength to support the mechanical load exerted by the rider as well as sufficiently stiff to withstand the vibrations that occur as a result of the riding process. A perfect material in this case ought to have a high tensile strength as well as a high Young’s modulus to offer the required qualities. 6. The material used has a low tensile strength and a high young’s modulus. The effect of the combination of a low tensile strength and high young modulus is that the material is sufficiently stiff to stretch but can only support a lighter load. The best improvement for the material would be to increase its tensile strength so as to make it support slightly high loads with regard to its high young modulus. A material with a high young modulus and a high tensile strength supports a higher load and does not easily stretch. 7. The component, as identified from the earlier calculations and experiments is made of an aluminum alloy. Similarly, aluminum has a low tensile strength and a high young modulus, meaning that though it is stiff it can support a limited load. Since the project requires the head engineer to provide a component for a Downhill Racing Mountain Bike, the initial establishment is that Aluminum would be so light when ridding downhill and is likely to breakdown due to the exerted weight of the rider. Hence, as a head engineer at Giant Bikes, I would suggest the replacement of Aluminum with Titanium. Titanium offers two major advantages; it has a high young’s modulus and a high tensile strength hence less likely to break down irrespective of the exerted weight. The second advantage is that due to its high density, aluminum is heavier and hence, the overall weight of the material adds up to the overall mass and thereby increasing the speed of the bike.(Acceleration is a product of mass and velocity) (Prasad, Ramakrishnan, & National Conference on Composites, Science, and Technology, 2000).) 8. When considering sustainability, the objective is to pick out the material that is both strong and durable despite the cost. After arranging by price, the cheapest of the 10 materials was found to be “Titanium, alpha-beta alloy, Ti-3Al-2.5V (Grade 9)” Reading the datasheet, “Titanium, alpha-beta alloy, Ti-3Al-2.5V (Grade 9)” is also used in bicycle frames, this is the perfect material to select when redesigning the part. The datasheets of the other materials were read and their main uses were for the medical industry (Kreider, 2016). 9. At a group level, we identified “Titanium, alpha-beta alloy, Ti-3Al-2.5V (Grade 9)” as the best suitable alternative. My personal evaluation of the alternative deign is that it provides improved mechanical properties to the principle design. In order to further improve on the initial design, I would propose the incorporation of a double frame made of Titanium, alpha-beta alloy, Ti-3Al-2.5V (Grade 9)” to further increase the strength of the seat post. The explanation behind the suggestion is to incorporate a double is that despite the strength and density of Titanium, alpha-beta alloy, Ti-3Al-2.5V (Grade 9), the mechanical vibrations during riding might easily waken the alloy. The double frame would thus help the component to absorb the resultant vibrations and minimize their effects on the component structure (Davis, 1994). QUESTIONS BASED OFF THE WEEKLY PRACTICAL’S Figure 1: The Iron-Carbon Phase Diagram 1. The Pearlite Phase and the Ledeburite Phase 2. Ledeburite () Phase 3. Austenite () Phase 4. Cracking is the process whereby complex organic molecules are broken down into simpler molecules by the breaking of carbon-carbon bonds in the precursors. Cracking was the type of fracture experienced when the water quenched 1045 sample from elevated temperature since the tensile strength is lower than the residual tensile stress in this case (Kreider, 2016). 5. Water quenching increases the ferrite characteristics of the steel alloy. On the other hand, the air cooling of the 1045 sample produces the austenite properties of the 1045 steel alloy. Basing on the Iron-Carbon Diagram, the ferrite phase has stronger properties than the austenite phase (Davis, 1994) 6. Degree of crystallinity = ((Delta Hf - Delta Hc)/Delta Hf,100%) x 100%. Where Delta Hf is the enthalpy of melting, Delta Hc is the enthalpy of crystallization, and Delta Hf,100% is the enthalpy of melting for a fully crystalline polymer (Liu, 2005). Since the different enthalpies are not stated, the percentage crystallinity of the polymer can be obtained from the graph. Extrapolating the graph, the percentage crystallinity is between 60% -70%. 7. LDPE with numerous branches within its chain structure has a low density due to the loosely attached polymers structure since the forces of attraction between polymer molecules are weak. On the other hand, LHDE which has few branching chains of the polymer has a higher due to the strongly packed structure and the forces of attraction between polymer molecules are strong (Krupp, 2007). 8. The service temperature is a material characteristic which provides information about the thermal stability of a material. The service temperature for polycarbonate is between 1400C - 1600C while for the high impact polystyrene is approximately 2000C. this basically implies that polycarbonate is thermally stable at about 1500C while polystyrene is thermally stable at 2000C 9. Glass Transition Temperature represents the temperature at which the individual polymer chains become sufficiently mobile at a molecular level to move independently despite the fact that they remain entangled. The melting point on the other hand is the temperature at which a given material changes from a solid to a liquid, or melts; the same temperature as freezing point. The difference in glass transition temperatures emanates from the fact that Polyamide 6 (Nylon) is a semi-crystalline polymer while polycarbonate is amorphous. On the same note, polycarbonate exhibits only one transition temperature while experiences two distinct transition temperatures (Cullen, 2005). References Cullen, W. H., ASTM Committee E-9 on Fatigue., & ASTM Committee E-24 on Fracture Testing. (2005). Automated test methods for fracture and fatigue crack growth: A symposium sponsored by ASTM Committees E-9 on Fatigue and E-24 on Fracture Testing, Pittsburg, PA, 7-8 Nov. 1983. Philadelphia, PA: ASTM. Davis, J. R. (1994). Aluminum and aluminum alloys. Metals Park, Ohio. Donachie, M. J. (2000). Titanium: A technical guide. Materials Park, OH: ASM International. In Tyagi, R., & In Davim, J. P. (2015). Processing techniques and tribological behavior of composite materials. Kreider, K. G. (2016). Metallic Matrix Composites. Elsevier Science. Krupp, U. (2007). Fatigue crack propagation in metals and alloys: Microstructural aspects and modelling concepts. Weinheim: Wiley-VCH. Liu, A. F. (2005). Mechanics and mechanisms of fracture: An introduction. Materials Park, Ohio: ASM International. Prasad, R. C., Ramakrishnan, P., & National Conference on Composites, Science, and Technology. (2000). Composites, science, and technology. New Delhi: New Age International. Read More