Manufacturing Materials and Its Selection - Coursework Example

Mechanical Engineering Name: Course: Instructor: Institution: Date of Submission: Manufacturing Materials; Mechanical Engineering The material selection process is included in the processes of designing the physical objects. The disk brake is a brake that employs calipers to squash pads beside a disk to generate friction delaying the cycle of the shaft. The material selection process assist in selecting the best product for the task ahead. The selection includes assessing a wide and narrow range of candidate materials in the manufacturing of disk brakes. Usage of metal today in the manufacturing of numerous products is vast. When manufacturing an automotive brake disc several materials have to be considered. The key components of a brake disc include the brake pads, disc, and caliper. The disc brake system is used in a number of locomotives including jumbo jets and others. Figure 1: Disk Brake The disk brake is a product whose manufacturing process involves assembling different parts that are manufactured differently in different processes. The disk brake separately has the shape of a circle. The main material used in its manufacturing is the cast iron. Cast iron is an effective material when considering antiwear performances. However, in terms of the performance of the locomotives, the material is of poor quality based on the weight of the material, which reduces the performance of the locomotive. The material is often replaced with a ceramic material, which is heat resistance and much lighter. Thus, it improves the performance of the locomotives. Candidate Material and Selection Disk brakes were formerly manufactured from burning of molten brittle ceramic materials. However, today, the main materials used in the manufacturing of the disk brake include short carbon fibers, heat molded resin and carbon powder. Silicon materials are added when the disk brake shape has been attained. The main purpose of the silicon is to harden the disk brake. On adding the silicon to the disk brake, the end material perceived is perceived as the silicon carbide. The main materials that are used in the disk brake manufacturing are presented as: Ceramics: The materials consist of carbon ceramic materials that lead to the silicon carbide. The key advantages include that it weights is less thus, does not negatively affect the performance of the locomotive. The brake response is improved including high thermal stability and corrosion resistance than that of the cast iron. The life cycle of disk brakes manufactured through carbon ceramics is longer and effectively avoid brake dust. The key disadvantage of this material is the cost, which is way higher compared to other materials in the market (Maleque, 2010, 123). Steel: The steel metal is effective for disk brake manufacturing. The manufacturing of the disk brake while using the steel material is easy due to its mechanical properties and the friendly cost. Some steel metals are good for high-temperature strengths while others are only good for mild temperatures. The advantage of the steel metal is developing disk brake is the high resistance to corrosion and heat. Others include the weldability and heat treatability of the material. Cast Iron: The main advantage of the material in manufacturing disk brakes is the good castability of the material, high resistance to corrosion and low cost and melting point. Titanium Alloy: The material is also similar to the ceramic material due to its high performance. However, like the ceramics, the titanium alloy is expensive for developing disk brakes. Like the ceramics, it is used in developing disk brakes for expensive locomotives such as luxury cars (Maleque, 2010). Aluminum composite: The material is considered better for manufacturing disk brakes. Some of its advantages include long durability, high heat dissipation, and light weight. Thus, it does not influence the performance of the disk brakes negatively. Narrowed Comparison of Candidate Materials The comparison is between the use of cast iron and ceramic materials in the development of disk brakes. According to (Ashby, 2005, 81), when selecting a material, factors such as strength, resistance to corrosion, cost, and density among others must be considered. According to the Ashby Chart, the material with the maximum loading index is selected. The Ashby chart considers factors such as dimensional, material constraints among other free adaptable constraints. Cast Iron The cast iron is the most common material found in disk brakes. The material is best suitable for issues regarding cost and eco-friendliness. The iron has nodular graphite, which assists in thermal dissipation without degrading mechanical properties. The manufacturing of the disk brake using cast iron is easy and ensures thermal stability. Thus, suitable for numerous locomotive disk brakes (Maleque, 2010). Ceramic Materials Ceramic materials are used in the production of disk brakes as well. However, unlike cast iron, the ceramic materials are expensive. The main advantage of using ceramic disk brakes is that corrosion and heat (friction) resistance is high. Fading is not experienced even when the material is under high loading. The Ashby Selection Strategy The modulus to consider in the Ashby chart includes strength and density. Strength is considered in terms of cost, toughness, and fracture of the materials. The two materials to be considered for selection include iron and ceramics. According to Ashby, the selection occurs in four key approaches (Ashby, 2005, 84). That is; translation, screening, ranking and supporting information. Translation It is attained in four parameters. That is; the function, constraints, objective and free variables of the materials. Thus, the function of both ceramic and cast iron in this process is the manufacturing of the disk brakes for friction emission. The constraints for the cast iron is weight, which impacts the performance of the disk brake. On the other hand, the constraint of the ceramic is the price. The material is too expensive to be implemented for disk brakes. The objective is to provide cost-effective and eco-friendly disk brakes while resisting heat and corrosion. At the same time maintaining a stable thermal dissipation. Thus, variables to consider include density of the material, corrosion and heat resistance, strength, toughness and fracture among others. Figure 2: Ceramic material properties (Maleque, 2010) Figure 3: Cast iron properties (Maleque, 2010, 95) Screening Screening involves using both the materials selected for elimination. The screening process is effective when dealing with more than one material as a candidate for the end product manufacturing. The material for the disk brake as presented here must be environmentally friendly besides meeting other property requirements. That is; the material should meet heat and corrosion requirements besides the cost of the materials in the market. Ranking In ranking, the best material to be selected is the one with the lowest density. Metal has a higher density compared to ceramics whose density is quite low. Thus, the material to be selected in this stage is the ceramics for its low density. However, based on the final supporting information, the selection process will be finalized between metal and the ceramics. According to young modulus, the material selection process is also attained through the geographical and graphical process. The mathematical process uses performance index in the ranking stage (Ashby, 2005, 97). The performance indices of materials occur in the form of: M =Pa1 / P2 The form is presented logarithmically as; Log (P1) = 1/a log (P2) + log (M) The modulus line is plotted with log (P1) against log (P2) M = materials with similar indices appear on the straight line plotted with 1/a gradient Figure 4: Young Modulus Line Materials on the line E1/2p perform well and are light. Those above the line perform better and those below the line are poor performers. Thus,in relation to ceramics and metal, metal is a poor performer while ceramics is ranked as a high performer. Thus, ranking using performance index selects the ceramics material for the task. Supporting Information Cast Iron is the best material and the selected candidate for this process. However, given that its weight is more than that of ceramics, and that the performance of the ceramics is much better, the selection process is questioned. The ceramics have all the best qualities to be selected as the main candidate. The main problem is the cost, it is an expensive material used for luxurious products mainly. Thus, commercial locomotives would not benefit by using this product. Therefore, given that the problem with the cast iron is density, which influences the performance of the disk brake, it will be selected for this task. Ceramics is the best material that should be used, but it is way expensive for this task. Figure 5: Ashby Chart for the Cast Iron Metal and the Ceramics References Ashby, F. M., 2005. Materials Selection in Mehanical Design. 3rd ed. New York: Pergamon Press. Maleque, M. A., 2010. Material Selection Method in Design of Automotive Brake Disk. London: WCE. Read More