Manufacturing and Materials Process Selection - Coursework Example

Manufacturing and Materials Process Selection Executive summary The various types of process involved in the component manufacture include joining, shaping and surface treatment. These are also divided into different subcategory in order to be specific in the various processes involved. For example fasteners, casting, machining, powder methods. CES is the best software used in the selection of these processes and the type of material used. Since different materials have various properties, CES can differentiate for each material and determine the process involved. This is done by drawing the graph. Scope of Study The study is majored on any one component selected from the prototype front end of an Aston Martin (including crash beams). The physical model on LG, front and rear is viewed and also the side and front end, showing longitudinal beams is viewed. Background Information King Swan is a successful and a perfect multinational engineering firm that perform a variety of engineering works in different sectors. They are known for their production of high-quality products to their customers and also their suppliers providing them with the component. As a contractor in the king Swan Company my research work will have an impact on the global economy since the product or component selected is the best, this is only possible after taking appropriate material and manufacturing selection process and carrying out the correct component design. As a consequence, it will create competition in the market, attracting more customers. The component that was studied was the prototype front end of an Aston Martin using genuine parts considering manufacturing specification. The component consists of many materials, and it considers many manufacturing process in order to produce parts that are highly profitable. In order to carry out the best material and manufacturing selection, software known as CES (Cambridge engineering selector is used). It is provided with a database of a wide variety materials and manufacturing process. (P.K, 2010) It also gives extra details of the materials; categories of the materials. Any material can be selected from the database with their properties both physical and mechanical. From that the best manufacturing process can be identified in order to come up with the best design possible. (Dixon & Poli, 1995) Functions and Operating Environment of Front End and Rear End Front end depends on who make it and the manufacturer specifications. The component consists of many sub-assemblies including structural front head carrier, radiator, engine cooling fan system and electrical wiring system. The main function of front end module is to act as a body frame in order to protect the vehicle and people inside it in case of any collision. (Croover, 1996). Another function is to properly illuminate the front of the vehicle and to improve the appearance of the vehicle. The total assembly weighs 60kg and is cantilevered in cast aluminum shock towers. The joint of the front end also has to withstand crash loads but bumper act as a shock absorber. (Elsevier & Butterworth, 2010) The Operating Environment of the Front-End Maximum power output from the engine should be more than 700bhp and Torque should also be more than 700Nm. The operating temperature should be between -150c to 50oc. This will be in consideration of the type of materials used in the manufacture of front end. (Hayes & Wheelrght, 1979) Material Properties and Selection The component consists of different material with different properties. The materials were selected in preference to the function of the component. The most materials used in the manufacture of front end were composite, thermoplastic, steel and aluminum; this is because they match the front end functions. (Hilger-Hertley, 1981). Thermoplastic had high production rates via injection molding and the derived processes. Thermoplastic is entirely applied in engine manifolds acting as a shock absorber. Thermoplastic was also used in the manufacture of bumper that enhanced energy absorption. (Waterby & Ashman, 1991) Aluminum was the other material that was selected. It had high mechanical strength approximately 700Nm to withstand the maximum stress encountered. Aluminum also operates under low temperature below 0oc since it does not even become brittle at such temperature (Hyes & Wheelright, 1984). The high melting temperature of aluminum enables it to operate in high extreme temperature without affecting the structure of the component (Hill & Terry, 2000). Weight does not affect its strength. Steel was also used to manufacture the front head carrier, because of its high strength capabilities to resist any loads in order to prevent the component from deforming. Identifying the Materials using CES Software Different materials were used in the manufacture of the component including radiator, engine cooling system, front carrier and bumper. The different material had different properties depending on their physical mode. In order to identify their physical properties, software is used to select the best for the given component. CES is considered as a material selection tool, in order to select material using CES icon had to be booted on opening the following dashboard resulted in (Cebon & Ashby, 1992). Figure 1 The icons represent different levels and were chosen according to specification. In browse mode level information about the material or process was found. This was further found by clicking material universe. Figure 2 By clicking material universe different material classes were found; ceramic and glasses, fibers and composites, metals and alloy, polymers and plastics. Figure 3 Each category was opened to further investigate individual members. For this case metals was opened giving the following; non-ferrous metals, aluminum metal, wrought alloys, 6000 series, 6060 alloys and T4 or T6 (heat treatment). Figure 4 Since aluminum was the major area of study under metals, it was selected and its properties identified. By clicking T4 alloys the following dashboard with the properties appeared. The process was repeated to find the properties of the remaining material; steel, composite such as thermoplastics and also ceramics. From the software, it was evident that aluminum and it alloys had got high tensile strength and compressive strength to increase its hardness (18.5 – 21.5Mpa respectively). This makes it suitable to be used in the front-end. Fatigue was also found to be high to resist any stress encountered (44.8 – 48.5Mpa respectively). All these properties aid in the protection of the whole car and its occupants. Physical property only one property of the material was identified which was found to be low. This property helps in the easy operation of the material when being worked on and reduces the weight of the entire vehicle for easy mobility. Different processes of manufacturing process were also identified by doing a parallel search. This was also possible through the use of CES software. Component Manufacturing Route Component manufacturing route was only possible by carrying out appropriate manufacturing process selection. In CES software, it was necessary to switch from the material universe to process universe by clicking on the icon as indicated in the figure below. Figure 6 Different manufacturing methods existed for the manufacture of the component to be successful. The processes used were classified into 3 broad categories; joining, shaping and surface treatment (Ashby, 1991). The processes also had their subcategories in order to find the specific process that conform the material selected. The process of opening up the tree structure can be seen in the diagram below. Figure 7 Figure 7 shows different processes that were selected. In joining welding was selected, shaping casting was selected and finally surface treatment the process selected was surface coating and painting. The casting method identified is a high precision and the best method in the process of manufacturing aluminum alloys. CES software indicated a full description of the process using a clearly labeled diagram explaining its function. (Abel & Edwards, 1994) Plotting of the Graph to Determine the Best Processing Method In order to determine and restrict the selection and process selection the need had to be identified e.g. structural form. For instance, if the selection of aluminum alloys only the available materials was to be identified. This is only possible by clicking advanced graph stage wizard menu. Trees related to the material, shape, process, and structure were found within the tab menu as shown in the diagram below. (Ashby, 2014) Figure 8 In this case the selection was restricted to thermoplastic polymers only. This was done by plotting a chart with young’s modulus on the y axis and a tree expression on the x-axis restricting the materials of thermoplastic only (Ashby & Mike, 2014). The y axis would be defined as young modulus in the same way but the x axis was defined by. 1. Axis tab was chosen 2. The advanced tab within the new graph stage wizard was clicked 3. Within the set axis box, material universe was chosen 4. Polymers was opened up then plastic and lastly elastomers. 5. Insert was clicked hence the tree expression appeared. Ok was clicked to confirm and ok was clicked again in new graph stage wizard to confirm both axes. The following graph was created. CES as a manufacturing process selection tool Varieties of processes were identified in order to select the best manufacturing process for specific components in the assembly for e.g. bumper of the front head. In process universe shaping processes was selected giving different subcategories as shown in the diagram below. Process which was cable of producing articles with the range of section 3mm to 4mm was chosen. Y axis was defined as section thickness and the x axis was then used to restrict various processes to those capable of shaping aluminum, this was done via the tree menu. The y axis definition was straightforward. Under the y axis a range of section thickness was chosen as shown below. X axis was clicked and advance option chosen. The procedure followed was; Trees was clicked Material universe was selected from menu Non-ferrous Alloys tree was opened up Zinc was selected and insert clicked. For the manufacture of a car bumper that is also a component in the front ends. The materials used for car bumpers. They were made from aluminum, but plastics can also be used; glass reinforced polyester and polyurethanes (Mahmound & Farag, 2013). Plastics bumpers are more advantageous than their counterpart metal since they are lighter and can absorb energy in a minor collision. Considering that advantage plastic bumper was used. Its weight was between 4 and 10 kg and it had a section thickness of 5mm. The surface finish for the bumper should be 0.4mm. In the process of selection follows the same procedure for manufacturing through drawing of the graph of the mass range of material class. Thermosets and polymer matrix composites were selected from material class menu. The various processes found were; spray up, hand lay. BMC molding, injection molding, compression molding, transfer molding, reaction injection and central molding (George & Dieter, 1997). The process that can produce the desired shape and desired shape thickness was then sought by identifying the subset of processes (Pandey, 2012). The corresponding was divided into two sections corresponding to each shape in preference to the specification. In each section, the process that was capable of making a particular shape was plotted. The selection box provided specified the requirement of the section thickness. The next selection stage was determined by using a bar graph of surface roughness against process class. The selection box specified smoothness requirement that is a complex process (Yousef & Shahin, 2011). The following processes were identified; hand lay-up process, cold press molding, BMC molding, resin transfer molding, Pultrusion, compression molding, injection molding and transfer molding. In order to produce the bumper cheaply one further step was required. This is where appropriate chart of economic batch size against process class (Ashby, 1992). Only discrete processes were plotted on the chart. The selection box specified a batch of size of 100000 for the bumper (Chetwynd, 1997). The processes that were capable of producing the bumper economically were as follows; BMC molding, compression molds, injection molding, SMC molding and transfer molding as shown below. There were various processes available for making the bumper though the manufacturing cost varied greatly (Ashby, 1989). The competitive processes that were used in large batch process include BMC and SMC molding, transfer molding, and compression molding. The decision factor was the batch size. Alternative Material and Manufacturing Process Steel is also another metal material that can be used in the manufacture of the component. Processes that can be done on steel are milling and drilling processes. Milling is the common form of machining. It is a material removal process that can create a variety of features such as holes, bending and reams. As before software known as CES can be used to select the best manufacturing process by following the procedure below. The process begins by clicking on the material universe in the level 3 database. Materials divided into five major groups can now be seen on the dashboard. Since steel fall under metal, the metal tree branch structure is opened. By clicking on steel different properties, can be identified including mechanical and physical properties. Steel has temperature resistance and high corrosion resistance and also high strength. Steel is heavier than aluminum this makes it have higher physical density. The type of processes can only be identified following the same procedure of switching from the material universe to process universe. This brings a dashboard containing three major categories; joining, shaping and surface treatment processes. The process of opening up the tree structure can be continued until the end of the branch in order to give specific processes on steel. The processes include cold and hot rolled process; these processes always involve heating and cooling steel without affecting its physical properties but increasing the strength of that particular steel. This is only possible since steel can support a wide range of temperature. The high strength prevents the component from the maximum load and stresses in the case of occurrence (Michael, 2006). Difference between the Component on the Physical Model and the Alternative Model There were many differences in the two-component model in terms of their structure, the means of joining the components and the manufacturing routes required. Since aluminum is a light in weight than steel, the method of joining to the other parts of the components are simple. This shows that the material can be easily machined than steel. Steel also requires many manufacturing routes than aluminum for example aluminum requires fewer processes in order to produce the best economic component with the lowest manufacturing cost. In the other case, steel needs so many and complicated processes in order to produce the same component. Because of the complex structure it had the highest manufacturing cost. (Ashby, 1999) Conclusion Most of the engineering components can be manufactured using different processes. The type of process will depend on the type of material selected, this called appropriate and accurate selection of material. CES software helps in the material and process selection through looking down into the material properties and determining the processes that can be used in the manufacture of the component. In the case of spark plug and aluminum cowling was studied and different processes were identified that can lead to the formation of the components (Ashby, 2000). CES provide a database where the material information if contained. This reduces the difficulty of straining in finding different properties of a particular material. In this study, various processes involved in material and component manufacture were identified. The processes identified were joining processes, shaping processes and surface finish processes (Asthana, et al., 2009). From the analysis above if the end component is more competitive in the market due to the process used then the cost of manufacture should be kept as low as possible. This can only be done through value analysis and value engineering. CES can narrow down by selecting the best manufacturing technique given the requirement, for example, the material properties. This is determined by drawing a graph of the material property against the primary process using CES. CES, therefore, provide the best selection method of materials and processes of different component. Bibliography Abel & Edwards, 1994. 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Engineering Design Process. second edition ed. Greensboro. Read More