CES: Manufacturing Process Selection - Coursework Example

CES Assignment Engineering and Construction SECTION INTRODUCTION 1. Materials Selection The task of selecting the right materials was done in CES selector system as a systematic approach after a study of the physical properties of the material as well as their behaviors in response to physical forces and external environment affecting the material. The selection was an application of diversity because the set of materials involved. The set contained hard material such as aluminum, copper, iron alloys, steel alloys and wrought iron. It also contained soft materials such as ceramics, glasses, plastic and polymer composite components. The choice of processes in the manufacturing also involved diversification by applying a combination of interrelated processes, design of shapes, economic implication of the processes and the performance of the designed products referred to as components in this study. The spectrum of methods available for the linking of the engineering materials and the selection of processes has to ensure both the weight and the surface properties of the components An example of what the experiment prepares is a heavy load-carrying container. This may need to hold the contents under pressure. The best choice of the materials is Aluminum or steel alloys to be able to sustain the weight. Plastic materials may collapse under such weight; hence they are not suitable for this task. Aluminum is strong, hard and durable, to make the container keep the load for longer time in spite of the weight. Lighter weights require light and soft materials such as plastic, ceramics and paper materials. For example, production of containers for liquid contents requires either glass or plastic for production of bottles. The criterion of choosing between the materials is whether the product will be able to sustain the weight and the pressure of the liquids. The decision to select aluminum alloys is derived from the mechanical properties as well as the physical properties of aluminum among other metals. In terms of the economics, Aluminum is more affordable among the material. Higher cost would imply that the project is not economically viable, hence less efficiency in spite of the high performance of the containers produced. The CES selector software assists in the combination of the appropriate materials according to the requirements. The choice of processes and materials are dependent on each other, such that certain materials have to be used in specific processes. Process Selection After picking the materials, the choice is followed by choosing the process from the process universe and the available sub processes. The major focus is to combine the materials and processes to develop the desired performance at the lowest cost possible for the manufacturing the required component. The factors looked into in the selection include the production stages at any time. At the same time, the process choice takes into account the safety measures to prevent any physical damage and injuries on the people present. This project selects two processes; deformation and welding from the process universe in consideration of the property of aluminum, being able to change shape without breaking up. This experiment does not require hardness. Aluminum simply requires a little force to bend but produces stronger products. The selection of process was done with the CES selector system, being the best computer application to correlate the mechanical features of the materials and process as well as the performance of the components manufactured. The products made in this project includes high pressure container to transport liquids. The second product of choice is carton boxes made of paper materials, to carry books. The choice was guided by the features like the lightness and softness of the box and its correlation to the required strength, availability and affordability of the materials. The question asked in the choices of process how strong the containers are and how light are the books to be carried by the carton box. The second question to ask is the value of the products. This CES Selector plays the role of combining materials is to combine the materials that can be welded to make the aluminum containers and the other light materials for production of carton boxes. It assists in the selection of the processes as well as materials such that each method demands selection of certain materials to satisfy the questions asked in the present experiment. The possible substitute of this method is a waterfall method, in which the processes begin from the initial stage then the rest of the stages follow in a sequence. The next process only begins once the present project is finished, instead of carrying out all the processes in one go. Direct reading of the measures supported the test of quality in the various materials from the instruments used in the measurement and the cost of the materials. PART 2: THE ACTUAL TASK This experimentation project made use of the CES Selector system in selecting materials as demanded by the processes at different stages of the component production. The main aim and purpose of tests was to measure the density of the nonferrous and ferrous materials and then to test the ratio of the Youngs Modulus, tensile stress, yield pints and the density of the materials. The CES Selector creates a condition for such measures in favorable navigation and selection of processes and the right appropriate material. The most important action in this project is to identify the performances and potentials of the material through the results of the correlation analysis, using two variables. The variables include the hardness of the material and the density of the material properties and the basic mechanical requirements as desired for the components products. The CES selector thereafter helped in the choice of the plotting for the correlations analysis. Indeed, the plotting shows that the project is feasible and attainable. The density gives the ability to prevent any form of penetration emerging caused by the mechanical properties. These include tensile strain and the tensile strength of the material used before it is placed in an actual manufacturing process. 2.1. Defining the Task Task 1: Navigation the Processes Sub Processes Figure 1: Process Universe Figure 2: Sub Processes The chosen processes in this experiment include mechanical welding, deformation and molding. 2.2. Processes Summary 2.2.1. Welding The selected process in this section is mechanical and physical welding. From this process and its sub processes, the container gains its physical shapes during the application of high temperature and pressure in the manufacturing steps. The aluminum, as the chosen materials allocated for the welding process and sub processes, includes aluminum and copper. The target containers to be produced from the selected processes of welding are expected to be as follows: Size: The products are similar to the materials applied in hardness and have the same size and weight Shape: The process of welding transforms the component into the required shape because of the elasticity of the aluminum materials and the intense heat applied in the welding. Dimensional Tolerance: The dimensions of the product can change at any time depending on the external pressure and temperature, both in the external and internal surfaces. Economics of the Process: The welding process is extremely expensive because of the soldiering materials involved. It requires heavy spending since the manufacturing process has many stages. 2.2.2. Plaster Molding Molding process will alter the material properties during the formation of the component, but not in a permannent way. The component can be transformaed different sizes and shape as desired by the molder. The materials selected for the process of molding include concrete, bricks, limestone and plastic. The components designed from molding will be of the following charactersistics: Size: The quantity of the items made from molding process will be less than the original size of the material because of the heat applied on the material during the drying and hardening stages. Shape: Molding leads to component with completely different non reversible shapes. Therefore, the shape is permanent since the materials are flexible. Dimensional Tolerance: The dimensions of the component dimensions are not alterable except during the destruction of the component using heavy forces and external pressures. Economics of the Process: The process is not costly. It is cost effective since ceramics and plastic materials are easily avaliable at lov proces. Additionally, very few stages are involved in the moulding process. 2.2.3. Composite Deformation The process of composite deformation literally implies the act of subjecting the chosen material to permanent reshaping using automatic process, by converting the materials to the desired components. The selected material for the composite deformation is bronze, copper, brass, aluminum and low alloy steel. The properties of the components produced through deformation include: Size: The component maintains the size and quantity of the material but depending on the material used, it can also loose some of the material and remain less than the original material Shape: The deformation makes a component with completely different shape from the material used. The shape acquired in the deformation is permanent. Dimensional Tolerance: The dimensions of the components are unchangeable. Economics of the Process: The peocess of deformation is costly as it involves application of heat and heavy defroming force. It also has a lot of risk attached to it because of the forces and external pressures that can cause injury. Safety precaution is therefore necessary and is expensive to implement. Part 2: In-Depth Processes Selection using CES Selector 3.1. Manual Process Selection The CES selector software was used in the selection of processes and sub processes from the process universe. The selection of each process determined the selection of the required material to accomplish it. The selected material and the properties are based on the correlation between the hardness (density) of the materials and the desired performance and behaviour of the proposed component. Figure 3: Selecting the Processes The next acrivity is to plot the data with two fundamental variables, the material density (hardnes properties) against the materials Young’s Modulus. The task is performed iteratively for the purpose of verification of the results. The gradient of the line plotted in the graph gives the corelation coefficient between the material strength and the desired performance of the resultant component produced during the manufacturing process. The plotting of the density anganist young’s modulus is shown in figure 4 below. Youngs Modulus Density (Hardness) 0 30 0.2 60 0.4 86 0.6 100 0.8 104 1 106 1.2 107 Table 1: Density Vs Young’s Modulus Figure 4: Hardness Properties Vs Young’s Modulus The hardness of the metal alloys used in the manufacture of the cointained was less than the ferrous metals and the nonferrous metals. This of course confirms the results of the plotted graph in the CES selector system (Machover 2001, p. 64). The selection found that bronze and copper were harder and stronger than cast iron. Likewise, the cast iron was found to be harder than the breakable ductile iron. The materials were thus arranged in the hierarchy of their hardnbess and performance providing a range of densities that support the selection of materials with reference to their hardness properties. In terms of the material density, steels alloys greater densities compated to the bronze and copper alloys. In the same order, copper ad bronze are harder than limestonr, cement concrete, ceramic bricks and plastics (polymers). 3.2. Computer-designed Correlation of hardness and Quality of Performance The CES selector was used in plotting of the elastic limit of the material against their densities. This is shown in figure 5 drawn below. There exists a strong and significantly positive correlation linking the elastic limit of the materials and their densities (hardness). The hierarchy of density reflects a dectresing order of hardness downwards from aluminum to Bronze, then to copper, then the low carbon alloys of steel, and finally polymers (plastics). This shows the elastic limit of each of the material (Gaskell 1995, p. 54). The elastic limit simply refers to the greatest amount of strength required by a metal to be able to deform the material elastically. However, there is a strong positrive correlation between the elastic limit and the materials’ yield strength. The yield strength is the amount of tensile stress needed for the identification of the beginning of the process of plastic deformation. As shown by the red line in the graph in figure 5 below, the pre is a strong positive linear correlationship between the elatic limit (yield strength) and the density of the material. Figure 5: Plot of Elastic Limit (Yield Strength) VS Density In the same way, there is a very signifiucant and strong positive relationship between the yield strength and the tensile strength, defined as the ratio of the heaviest load and the physical area of the surface under the load. This of course explains the analogous relationship between the material density and the tensile strength (Dieter 1997, p. 42). Figure 6: Tensile Strength against Hardness of mixed Materials Figure 6 above presents the linear associaltion between the tensile and the strength and the density of the materials (Callister 2000, p. 62). This gives the linear relationship between the properties of the materials and the obtained values of the tensile strength for all the selected materials. The physical geometry of these materials and the properties of the propesed components readily enable the testing of hardness together with the uniaxial tensile strength. Figure 7: Yield Strength against Hardness However, there is a positive and significantly strong association between the Yield Strength and the hardness of the materials shown in figure 7 above. The chart in figure 7 above shows the energy consumption related to each of the materials. Energy saving is achieved by minimizing the amount of steel or concrete and production of more efficient design of structure. 4. Presentation of the Overview Eco Audit Tool in CES Even though the materials consume the energy differently, carbon materials are expected to be the generator of most of the energy. This is the reason why construction and design of durable components will lead to selection of non-carbon materials. Where carbon materials must be used, the quantity must be reduced to the minimum. Materials such as concrete and steel are dominant in the production measured by the total tonnage. For the components that require soft materials, the available choices are softwood, plastic, ceramics or concrete, depending on the process that demands them. In the structural engineering project, the central material is wood. An accompaniment of water is required in various quantities. Figure 8 below shows a plot of the consumption of water. With the eco properties, the eco audit tool shows the materials according to their values, from the highest to the lowest value. Figure 8: Water consumption by various materials 4.1. Procedure While on the section of primary material production, the first step is to click on the bar, move to the record then scroll downwards to the water consumption. A person clicks on the title Water consumption and then studies the commercial water consumption for the specific selected materials. 4.2. Low Density Materials While considering the usage of water for facilitating the processing of natural materials, the water is found to be a content of many other materials such as wood. Trees contain water naturally until it dries up. Being sources of wood, trees and plants and their bi products are among the greatest sources of carbon. The products such as thermoplastics or cellulose polymers, polylactides, leather, starch thermoplastics are other components and products of less density carbon materials. Their processing requires water either commercially or in small scale. 4.3. High Density of Materials Most of the metals are obtained from natural mineral reserves, forming part of the economic construct that grow and reduce under various economic and legal conditions. Improved technologies of extraction enlarge the environmental laws and the changes in political atmosphere reduce the mineral reserves available, hence minerals become extremely rare and economically non- viable. This stimulates higher demand prospecting, resulting into the reserves tending to rise alongside the rate of consumption. The mineral resource is the actual total capacity of the resource available naturally, and generally exceeds the mineral reserve but its availability is not usually certain. It is inclusive of not only the present reserves but also the usable deposits. According to the eco audit tool, the prospecting the various methods of extrapolation have to be estimated, including the well-known or the unknown commercial mineral deposits as a result of the higher prices. The future recommendation is to have an improved technology for transportation for the future to make the minerals more available at better prices. Figure 9: Yield Strength against Energy and primary production * Hardness (Density) The plotting of the data shows the associaltion between the properties of the peroposed component and the propertics of the properties of the available materials. The CES selector was used as the principle eco audit tool to use the density of the available materials in the current project and perform a correlation analysis between the tensile strength and the elastic limit (Young’s Modulus) of the material (Ashby 2005, p. 52). Additionally, the linear relationship between the two variables measured was the statistical measure of the least-squares fitting in a computer aided design. The second eco-audit tool used in this project is the Microsoft Excel spreadsheet. The two eco audit tool were used in the simulation of the statistical and scientific models with the equation showing the linear correlation and programming of material mixing in the manufacturing. In this project, the model equation os association between the density and the hardness had a resultant coefficient of association as Cf = -0.5 * EL + 6 h, where h is the hardness and EL is the elastic limit. The eco audit tool begins with the analysis of the results for identification of the priorities, exploration of the available options, use of the CES selector for the selection of raw materials and the relevant production processes, then finally, recommendation of appropriate actions and assesscment of economic value of the entire exercise. Figure 10: Strategy of the Eco-Audit 4.4. Functions of the Eco audit Tool The principle function of the eco-audit tool is to permit the students to implement the assessment of the characters of the materials and products. For example, it views the Carbon selection strategies and the lifecycle of its products from the material to the distributed product then to disposal. The CES selector presents two sets of audit tools for the exploration of environmental setting and structure. The graph in figure 10 above shows all the processes in their sequence of execution and the amount of energy consumed by each process. It enables the selector to decide on the next process to select at every stage. The selection strategy enables the material selection to re-design the entire product set to satisfy the eco-criteria, with the application of the systematic methods. The eco-audit tools reveal the projected characteristics of the products and suggest the methods applied to make the products friendlier to the environment and reduce damages such as environmental pollution. The eco audit tools are available as open source applications for students and for commercial use in various online sources. 4.5. Solutions Provided The eco audit tools assist in the solution of various logical and technical problems in relation to the characteristics of the materials 4.5.1. Example of Problem Solved In one of the instances, this experiment investigates whether the embodied foot prints of CO2 Biopolymers and their energies are less than the conventional plastics. The eco audit tool provides a solution by presenting a strategy for use of bar charts representing the embodied energy and the carbon dioxide CO2 footprint to get plotting of the charts and access them by clicking on the Help and then making use of the Video Tutorials. 4.5.2. Alternative Solution Another solution strategy is to use the search option in the CES Selector to find the biopolymer. The search delivers the five materials shown below. The plotting of the embodied energies for the polymers demonstrates the fact that the initial two materials in the list have low embodied Energies than the rest of the polymers and elastomer. The comparable chart in figure 11 below shows the carbon footprint, revealing the fact that the gas (CO2) generated is related to the generation of the lower end of the polymers measured per Kg. The eco audit tool selects the Materials such as Polylactide, the Natural Rubber and the Cellulose polymers. Figure 11: Representation of the CO2 Footprint 5. Finding and Recommendation In the use of the eco audit tool to provide solution to problems, select the property heading of the material selector, the embodied energy and the primary production in order to find the definition of the property. The definition of the embodied energy is any energy apart from the bio-fuels, which is committed towards the production of the unit weight of each of the materials from their natural source form to the commercial form (Ashby 2005, p. 43). For any unclear challenge, the eco audit tool provides the search and the help facility, which a user clicks on and chooses the CES Help. In the search tab on the left side shows the Carbon Footprint with its definition. 6. Conclusion In conclusion, the CES selector tool has been found efficient in the systematic approach of material and process selection in the manufacturing exercise. The properties of materials place all materials in a sequential order of their strength, making it easier to locate the materials from the material universe. At the same time, the use of the eco- audit tool is justified because of its consideration of the holistic approach in the calculation of economic implication of the materials and the processes selected. It is also comfortable to use owing to the availability of the help and the search facilities. The choice of material is automatically set through the selection of the processes. If a process uses a certain material, then at the selection of that process, the demand of the relevant materials automatically presents the options of the specific materials for easy selection rather than redoing the selection from the entire material universe. Works Cited Ashby, MF 2005, Materials Selection in Mechanical Design. USA: Elsevier Ltd, p. 251. Callister, W 2000, Materials Science and Engineering – An Introduction (5th ed.). John Wiley and Sons. Dieter, G 1997, "Overview of the Materials Selection Process", ASM Handbook Volume 20: Materials Selection and Design. Gaskell, DR 1995, Introduction to the Thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. Machover, C 2001, "18". The CAD/CAM Handbook. Beverly Beckert. McGraw-Hill Companies. p. 26. Read More