Manufacturing Technology and Materials - Case Study Example

Manufacturing Technology and Materials Table of Contents Section 1 2 (a) 2 (b) 3 Section 2 3 (a) 3 (b) 4 Section 3 6 (a) 6 (b) 7 Section 4 11 (a) 11 (b) 11 References 13 Section 1 (a) An Exhaust Manifold is generally considered as a structure or an arrangement that is executed in order to emit exhaust gases away from a particular engine. The exhaust manifold usually extends from the cylinders to the exhaust pipe that is mainly implemented in order to collect as well as to remove the exhaust away from the engine. The chief function of an exhaust manifold is to detect any sort of exhaust leaks which is quite detrimental to inhale and there lies every possible chance for the people to inhale such exhaust gases without being attentive towards the fact. The exhaust manifold typically comprises a sequence of pipes which joins with the cylinders and then combines in a central big pipe which emits to the exhaust pipe. In this context, a wide chain of gaskets are being implemented in order to generate rigid seals so that the exhaust cannot break out from the cylinders. The major difficulty that might arise with the component of an exhaust manifold is basically the harm to the gasket which operates as a seal. The other significant problem that might arise from exhaust manifold is the factor of rust. In this context, if there lays any possible chance for occurring rusts then the pipes associated with exhaust manifold may get damaged and ultimately can begin to leak detrimental exhaust gases into the engine section. In a particular car, this sort of damaging exhaust fumes can greatly contribute towards making the passengers or the people sick by significant level (Mohiuddin & et. al., 2007). It is evident to the fact that every kind of vehicle possesses various kinds of functions that are directly associated with the overall performance that include engine, transmission as well as suspension and design among others. In this similar context, the function of exhaust manifold is directly linked with the engine of a particular car which removes the exhaust gases that are quite injurious for the passengers or the users. Additionally, the appropriate execution of exhaust manifold ultimately results in superior performance along with increasing the competence as well as the power of the engine of a specific vehicle (Auto Parts Corner, 2006). (b) It has been viewed that the automotive engines generally perform their mechanical functions under severe circumstances. The operating temperature fundamentally rises up to 8000 C from ambient temperature and as a consequence huge thermal stress can be experienced in the component of exhaust manifold. This particular problem is regarded as thermo-mechanical pairing in the field of automotive engineering. In relation to the aspect of stress and service atmosphere related temperatures of exhaust manifold, it has been observed that certain cracks can be found in the stainless steel body of exhaust manifold because of thermal exhaustion happening at a high temperature. Hence, the aspect of thermal exhaustion or fatigue has to be greatly considered as an important stress that generates while designing the procedure of exhaust manifold (Lee & et. al., 2004). Thus, it can be stated that thermal fatigue can be considered as one of the major stresses throughout the functioning of exhaust manifold. The aspects of temperature and service atmosphere of exhaust manifold lie in the fact that the exhaust manifold is such a component which helps to remove the damaging exhaust gases from the car. The component plays an imperative part because it is directly associated with the engine and it deals with the temperature of the exhaust gas which is quite high as 9000 C. In order to perform excellent service, the various significant properties that the component requires are outstanding oxidation resistance, high-temperature power and thermal stress removal properties. In recent times, it has been observed that the stainless steel is greatly used as a chief material especially for the exhaust manifold functioning system. This is due to the reason that the stainless steel generally provides superior performance at high temperature surroundings that comply with various social requirements in terms of cleaning exhaust gases along with ensuring greater fuel economy (Inque & Kikuchi, 2003). Section 2 (a) There are many different kinds of exhaust manifold that are created from nodular or cast based iron. In this context, there are certain exhaust material systems that are formed on the basis of heavy-gauge steel or stainless steel. In this regard, the other material requirements for the component i.e. of exhaust manifold generally include cylinder head gasket, front as well as flexible pipe, muffler, catalytic converter, tailpipe, heat shields and hangers, clamps as well as brackets. The exhaust manifold essentially contains a kind of exhaust related port which is involved in the cylinder head. It has been recognised that there are certain exhaust manifolds that possess a gasket attached with the manifold as well as the cylinder head. The exhaust gas that generates from the engine ultimately passes from each port that is present in the manifold into an ordinary single channel before reaching into the manifold flange. An exhaust pipe is linked with the exhaust manifold flange. An exhaust manifold is bottled to every individual cylinder head that typically can be seen especially on a V-type engine. The above discussed material requirements are vigilantly engineered for the purpose of delivering suitable as well as proper flow of the damaging exhausts along with providing appropriate functioning towards diminishing the emission levels of a particular engine. Additionally, accurate tuning of exhaust manifold would ultimately assist to collect as well as to draw the exhaust gases out of the cylinders and thus it dynamically improves the overall efficiency of a specific engine (Pickerill, 2009). Apart from the above discussed material requirements, the other most noteworthy as well as the vital material requirement of exhaust manifold is the implementation of stainless steel. The service conditions of exhaust manifold effectively facilitate to increase the engine performance with the use of the material component of stainless steel. It has been viewed that the material i.e. stainless steel is widely executed for huge number of automobile related components due to its excellent quality features that consist of outstanding performance towards corrosion as well as heat resistance functioning and also for high-quality service appearance (Inque & Kikuchi, 2003). (b) The conception of CES Software fundamentally depicts an exclusive PC-oriented software related product that supports well organised choice of different competent materials for various engineering applications. It is also considered as an exceptional instrument for the logical selection of certain engineering associated materials such as metals, polymers as well as ceramics along with other manufacturing procedures that include joining, shaping and finally finishing. The CES software primarily combines a record of various materials along with certain major procedural properties. The software helps to browse as well as to search any sort of information regarding the selection of materials along with creates superior visuals and charts in order to compare the various materials that are to be selected. Furthermore, the CES software recognises as well as ranks the most excellent materials for a particular engineering related application program (Cambridge Network, n.d.). The CES Software mainly determines the execution of various functions regarding the components, the major objectives that are required to be optimised and finally the constraints that must be satisfied by a considerable level. The chart relating with material selection generally plots one particular property against another. The chart provides a quick as well as visual representation of the comparative position for all the probable selected materials that are being considered towards executing any sort of engineering applications (Granta, 2012). A pictorial presentation of CES software is attached hereunder. Fig. 1: CES Software Source: (Granta, 2012). In relation to CES Software, among various effective materials, the most significant material which is preferred that is associated with exhaust manifold is the utilisation of stainless steel. This particular material i.e. stainless steel poses noteworthy impact as well as contributes largely towards the smooth along with successful functioning of exhaust manifold. The broad execution of stainless steel has been introduced especially in the automobile segment with the intention of complying with several communal related requirements that include providing uncontaminated exhaust gases along with delivering superior fuel economy. The use of stainless steel has been increased quite considerably and is executed for most of the parts as materials for the component of exhaust manifold. There lie various significant quality facets of the material i.e. stainless steel that include good appearance and superior heat as well as corrosion resistance power. These are certain decisive factors that ultimately increased the necessity of stainless steel to act as a major material in most of the parts belonging to automobiles sector. The major task of an exhaust manifold is to accumulate the exhaust gases from the individual engine cylinders and direct them towards the front pipe. The stainless steel material of exhaust manifold is classified into certain types on the basis of the procedure of fabrication. In this context, the exhaust manifold which embraces stainless steel is fabricated through the formation of welding as well as steel sheets and the other type of fabrication is done through bending effort of welding along with steel pipes. Among the different types of stainless steel, either ferritic or austenitic kind of stainless steel is executed for an exhaust manifold. In this regard, an austenitic class of stainless steel generally possesses excellent high-temperature resistance strength and the ferritic sort of stainless steel possesses outstanding oxidation resistance power. The temperature in relation to exhaust gas usually tends to increase considerably in future and as a result, there lies the requirement of the properties of various steel materials whether ferritic or austenitic along with the factor of thermal fatigue applications. Additionally, due to the factor of complicated shape as well as size of an exhaust manifold, superior formability may also be pursued or can be followed by large level (Inque & Kikuchi, 2003). Section 3 (a) The manufacturing procedure of any component plays an imperative part especially in the development as well as the advancement of a particular material or a system. The selection of proper manufacturing route ultimately raises the productivity along with the efficiency of the specific material. Thus, on the basis of the above discussed grounds, it can be stated that it is quite essential to emphasize more upon the selection of proper manufacturing routes of the components for better utilisation of the materials in any sort of technological applications. In this context, the different manufacturing routes for exhaust manifold fundamentally include realistic appliance of super heat-resistant type of steel (NSHR-F), the formation of flash-free related casting skills and the development of aluminium alloy castings. Moreover, the other manufacturing routes also include the introduction of a computer-support based solidification simulation arrangement (SCAST), the advancement of logical execution of new cast steel exhaust parts for cleaning auto engines and finally the development and practical appliance of new pressure diminished atmosphere casting (HMRAC) by using sand molds. In addition, the other manufacturing route which has been developed recently in relation to exhaust manifold is regarding the execution of the manufacturing procedure by means of a vacuum-assist gravity pouring technique (Flemings & et. al., 1997). (b) The CES process selection procedure generally involves three levels of databases that assist towards justifying the final route of manufacturing process of stainless steel material for the component of exhaust manifold. In this context, level 1 of the CES software in relation to process selection depicts the description, application as well as image of the material wherever applicable. Level 2 signifies more extensive design guidelines, numerical based data, technological notes and various ecological related properties. Level 3 of CES software with regard towards process selection generally portrays widespread numerical presentation for all the materials, permitting the full power of the CES selection system to be deployed. At the time of opening the CES software, a particular level is asked for to be selected and the process selection can be started by selecting Level 1 (Granta Design, 2007). The above mentioned three levels can be interrogated by following certain effective steps in relation to process selection based upon CES software. The first step is browsing the required material in which record for various materials are available that includes stainless steel, concrete and polypropylene among others. Fig. 2: Browsing (1ST Step) Source: (Granta Design, 2007). The second step is about searching information regarding the procedures that include injection molding, friction welding and laser surface hardening among others. Fig. 3: Searching (2ND Step) Source: (Granta Design, 2007). The third or the final step is regarding the process selection. Thus, on the basis of the above discussed grounds, it can be stated that the CES process selection greatly emphasises upon the significant steps that include browsing, searching and selecting by a considerable level (Granta Design, 2007). Fig. 4: Selection (3rd Design) Source: (Granta Design, 2007). A graphical presentation of the levels of CES process selection is provided hereunder. Fig. 5: CES Process Selection Source: (Granta Design, 2007). Section 4 (a) There lie various manufacturing routes for the component of exhaust manifold. Among the broad variety of manufacturing routes for making the component of exhaust manifold, the realistic appliance of super heat-resistant steel (NSHR-F) has been selected. In this similar context, the introduction of heat-resisting steel such as Hercunete-S A3N is based upon austenite related cast steel that possesses highest strength at over 6000C and exhibits the greatest oxidation resistance rate at 9000C. Moreover, along with possessing the capability of greater oxidation resistance power as well as superior performance particularly at high temperatures, the heat-resisting steels also bear high thermal exhaustion strength that acts as an effective property towards the manufacturing procedure of exhaust manifolds. Due to these enhanced as well as quality facets, the heat-resisting steel such as Hercunete-S A3N is greatly applied as one of the competent manufacturing routes towards making exhaust manifolds. It has been observed that an existing exhaust manifold can develop several functions that include oxidation, thermal related cracks or deformation and for this particular reason, the application of heat-resisting steels are normally chosen as the manufacturing route for exhaust manifold. However, by considering the important fact that the temperature of the exhaust gas in relation to exhaust manifold can reach up to 10000C (18320F) for a particular engine, the functioning of heat-resisting sort of steels can play a vital part. Therefore, in order to comply with the performance demands of the modern engines, the heat-resisting steels like Hercunete-S A3N has been chosen as a manufacturing route for exhaust manifolds (Hayashi & et. al., n.d.). (b) The application of the heat-resistant cast steels associated with the manufacturing procedure of exhaust manifold tends to be highly sensitive due to its certain significant facets relating with the factor of oxidation resistance, thermal fatigue and power to act in relatively high temperatures. These crucial features of heat-resistant steels ultimately influence the microstructure of the material i.e. stainless steel while manufacturing the exhaust manifolds. The manufacturing procedure of exhaust manifolds that generally includes setting the pipes, mandrel bending, construction of the muffler, welding and finally packaging ultimately influences greatly towards the microstructure of the material as well as the material component (Hayashi & et. al., n.d.). The most important characteristic defect that might arise during the manufacturing method of implementing high-quality steels towards the formation of exhaust manifold is regarding the leaks in the exhaust manifolds that often transform into cracks in the cast iron due to the factor of intense temperature. An exhaust leak might prove to be hazardous as well as problematic for the environment as well as for every individual. Moreover, the other defect can be regarding the emergence of mechanical exhaustion during the manufacturing process of exhaust manifold. In this context, the oxidation related issues through the execution of various effective materials can also contribute towards causing the defect while manufacturing by the method of heat-resistant steels for the production of exhaust manifold (Hayashi & et. al., n.d.). In order to minimise or to avoid the above discussed defects, the possible solutions can be cleaning all the contaminants from the used materials during the manufacturing procedure before the practice of welding, replacement of the material if possible and repairing of the cracked components. Moreover, the other remedial measures also comprise proper selection of the welding parameters along with several techniques in order to produce better performance of the welding procedure and ensuring the utmost concern towards delivering sufficient resistance to the solidification stresses. In addition, the measures also include discarding high speed of welding particularly at a higher level, ensuring adequate filling of the crater in order to avoid any such further defects in future and finally controlling the joint fit-up in order to reduce gaps (TWI Ltd., 2012). References Auto Parts Corner, 2006. Exhaust Manifold. Home. [Online] Available at: http://www.autopartscorner.com/exhaust_manifold/ [Accessed May 26, 2012]. Cambridge Network, No Date. CES Selector. Companies. [Online] Available at: http://www.cambridgenetwork.co.uk/directories/companies/368/products/845/ [Accessed May 26, 2012]. Flemings, M. & et. al., 1997. Final Report. Advanced Casting Technologies In Japan And Europe. [Online] Available at: http://www.wtec.org/pdf/casting.pdf [Accessed May 26, 2012]. Granta, 2012. Key Concepts Behind CES Selector. Products. [Online] Available at: http://www.grantadesign.com/products/ces/ashby.htm [Accessed May 26, 2012]. Granta Design, 2007. Thumbnail Sketch of CES EduPack. Courses. [Online] Available at: http://www.eng.cam.ac.uk/teaching/courses/y1/CES_Tutorial.pdf [Accessed May 26, 2012]. Hayashi, K. & et. al., No Date. Introduction. Niobium In Heat Resisting Cast Steel Auto Parts. [Online] Available at: http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_5/images/pdfs/053.pdf [Accessed May 26, 2012]. Inque, Y. & Kikuchi, M., 2003. Exhaust Manifold. Present and Future Trends of Stainless Steel for Automotive Exhaust System. [Online] Available at: http://www.nsc.co.jp/en/tech/report/pdf/n8814.pdf [Accessed May 26, 2012]. Lee, K. O. & et. al., 2004. Thermal Stress and Fatigue Analysis of Exhaust Manifold. Key Engineering Materials, Vols. 261-263, pp.1203-1208. Mohiuddin, A. K. M. & et. al., 2007. Optimal Design of Automobile Exhaust System Using Gt- Power. International Journal of Mechanical and Materials Engineering (IJMME), Vol. 2, No. 1, pp.40-47. Pickerill, K., 2009. Automotive Engine Performance. Cengage Learning. TWI Ltd., 2012. Defects-Solidification Cracking. Services. [Online] Available at: http://www.twi.co.uk/services/technical-information/job-knowledge/job-knowledge-44-defects-solidification-cracking/ [Accessed May 26, 2012]. Read More