Overview of the Materials Selection Process - Assignment Example

CES Assignment Engineering and Construction CES Assignment PART INTRODUCTION 1. Materials Selection The choice of materials inthe CES project in was conducted in by a systematic view of the material qualities and behaviors in relation to the desired components to be made. A good example is the preparation for production of the liquid containers. Because of the high pressure under which the liquids will be stored, the containers required to be made of Aluminum Alloys or steel instead of plastic materials. Apart from the strength of the aluminum, the other desired property was the durability, to enable the containers store the liquids for longer time. In the contrary, production of milk carton simply requires light papers. The guiding principle in the choice of the materials is the ability of the final product to sustain the physical forces during the testing. The decision to choose aluminum follows the study of the mechanical properties and physical behavior of aluminum. The second guiding principle is the affordability of the material, since high costs make the production of the container less efficient regardless of the performance of the component developed. The CES software aids in the selection of appropriate materials as per the requirements of the processes applied in the production of the components. 1.2. Process Selection After selecting the materials, the next phase is the selection of process, the major aim of this is the selection of the most appropriate and cost effective technique and for the manufacturing a the desired component (Callister 73). The factors considered in the selection are the stage at which the production is at any time, and the desired qualities of the component being produced. Of course, the choice of the process also takes into consideration the safety measures to be taken by the component producers. This experiment for example, selects the processes of welding and deformation considering the property of aluminum to undergo deformation without necessarily breaking. This experiment cannot other processes that require hardness, because aluminum bend under high pressure. The choice of the process is done with the aid of the CES as a computer-based application for correlating the mechanical characteristics. The components designed in the experiment are the high pressure container for liquid products and light carton boxes for paper and stationeries. The criteria of choosing a good process is the include features like affordability, minimal waste in the manufacturing process in order to avoid waste of economic resources. The question to asked when making choices of the process is the strength and the size of the pressure vessel or the paper carton. The second question is the cost and the demand of resource required in the design (Dieter 47). This experiment uses CES Selector to select the processes and plan for each of the process according to the choice of relevant materials. It helps select the processes and materials in the same way, whereby each of the methods refers to the questions initially asked in this experiment. The possible alternative of a methodology that is applicable in this project is a top down method approach, in which we begin with the arrangement of all the processes and select the materials in the as one of the processes instead of separating the process selection and material selection. The quality test of the materials including hardness is done by directly reading the digital display from the analog counter owing to the different penetration intensities in the test instances. PART 2: THE ACTUAL TASK This experiment involves the use of CES Selector system to select materials as well as the processes. The main objective and purpose of the tests is to measure the hardness of the ferrous and nonferrous materials pack in according to the international standards. The CES Selector system has to create an environment such that the conditions are favorable for navigation in both the processes selection and the materials the appropriate material selection. The most critical activity in the experiment is the identification of the behaviors and qualities of the material by running the correlation analysis of the material properties against the standard mechanical requirements of the desired components such as the hardness (Ashby 82). The CES selector assists in the selection and the plotting of the correlations. This is a feasible experiment. It is attainable and of value because the hardness gives certain capacity to resist the penetration emerging from mechanical behaviors such as the tensile strain and strength. 2.1. Definition of the Task Task 1: Navigation through the Processes and 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. Mechanical Welding The mechanical welding gives the physical shape of the manufactured components. The materials assigned for the welding are aluminum, plaster mold and copper. The target components produced from the mechanical welding is will possess the following features: Size: The components take the same size as that of the materials applied Shape: The mechanical welding can transform the component into any shape owing to the elastic nature of the materials. Dimensional Tolerance: The component can change from time to time due to external and internal pressure. Economics of the Process: The process involves heavy cost because of multiple stages in the process and the purchase of the materials. 2.2.2. Molding Molding will change the material into the component, but not permanently. The component can be reorganized into a different shape as per the desire of the contemporary need. The materials chosen for molding are aluminum and cast iron. The components made in the molding method have the following features: Size: The molding process retains the quantity of the materials such that the size of the components is the same as that of the material used. Shape: Molding makes the component have a changeable shape, so the shape is not permanent because of the flexibility. Dimensional Tolerance: The component dimensions are changeable depending on the prevailing external and internal pressures. Economics of the Process: The process is cost effective because the molding process involves fewer tasks. The only heavy cost is that of the materials. 2.2.3. Deformation Deformation literally means the selected material is subjected to permanent shaping through automated process in the conversion of the materials into the required components. The chosen material for the Deformation process includes aluminum and low alloy steel. The characteristics of the components produced through deformation include: Size: The component retains the size of the material used or loses some of its mass. Shape: The deformation leads to a permanent change in the shape because of the amount of pressure involved. Dimensional Tolerance: The components maintain the dimensions permanently unlike the process of molding. Economics of the Process: The deformation process is expensive because of the increased number of process stage and subtasks. Part 2: In-Depth Selection of the Processes 3.1. Manual Process Selection Each of the Processes is chosen individually and manually from the process universe. The choice of the process then leads to the selection of the relevant materials depending on their properties. Figure 3: Selecting the Processes The next task is to plotting the data using two parameters, the material hardness properties against the Young’s Modulus. All of the process tasks in this experiment iterated for the purpose of verification of the outcomes. The hardness (density) was plotted against the Young’s Modulus as shown in figure 4 below. Figure 4: Hardness Properties The density of the alloys was less compared to the ferrous metals. The same case was true for the nonferrous metals. This is in agreement with the results plotted in the CES selector system. The selection considered that iron and steel are harder than the cast iron. Cast iron in the same manner is harder than ductile iron (Gaskell 62). The order of hardness and the provided range of hardness are found to agree. In the reflection on the density, the cold steels alloys have higher densities than they hot rolled steel alloys. 3.2. Computer-Aided Correlation of Material Quality The CES selector was used to plot the elastic limit of each material against the density. This is presented in figure 5 below. There is a strong positive correlation between the elastic limit and the hardness. The hierarchy of hardness reflects an increasing order aluminum to copper and finally to the low carbon alloys of steel. This defines the elastic limit of a material as the highest stress that a metal is able to deform in an elastic manner. Even so, there exists a strong positive correlation between elastic limit and the yield strength. Yield strength is the amount of stress required for one to identify the start of the plastic deformation process. The red line in figure 5 shows the positive linear correlation. Figure 5: CES Plotting of Elastic Limit against Density Similarly, there is a strong positive correlation between the elastic limit and the tensile strength. The tensile strength is the ratio of the greatest weight and the area under the load). This is the reason for the analogous association between density and tensile strength. Figure 6: Tensile Strength against Hardness Figure 6 above shows the relationship between tensile strength and the density (hardness). This specific association between the properties of the materials subjected to detailed evaluation to obtain the values of tensile strength for all the chosen materials. The geometry of the materials and the intended components readily permit the test of hardness to test the uniaxial tensile strength. Figure 7: Yield Strength against Hardness However, there exists a strong relationship between the Yield Strength and the density of the materials in figure 7 above. Figure 8: Young’s Modulus against Density. 4. Presentation of the Overview Eco Audit Tool in CES The plots of data in the discrete cylindrical association are presented in the Rockwell density having values from 0 to 100, with a gap of 10 spaces units. The CES eco audit tool makes use of the density in the present project to do a correlation between the elastic limits and the Young’s Modulus. In addition, the linear association in the data is measured with the least-squares fit in and involving a computer application including Excel spreadsheet. The eco audit tool enables the simulation of the models and the equation representing the linear correlation between the elasticity and the density. The model equation used during the manufacturing process assists in the combination of materials in the right proportion, through linear programming. In this exercise, the equation linking the density and the relation coefficient obtained to be C = -0.050 * D + 6.51. Works Cited Dieter, George. "Overview of the Materials Selection Process", ASM Handbook Volume 20: Materials Selection and Design, 1997. Ashby, Michael. F. Materials Selection in Mechanical Design. USA: Elsevier Ltd, 2005. p. 251. Callister, William, Materials Science and Engineering – An Introduction (5th ed.). John Wiley and Sons, 2000. Gaskell, David R., Introduction to the Thermodynamics of Materials (4th ed.). Taylor and Francis Publishing, 1995. Read More