Construction Materials Analysis - Report Example

MATERIAL ANALYSIS REPORT By Name Professor Institution City State Date Summary The objective of this report was to study and exhibit the rationale behind the selection of various materials for various vehicle component. As such, materials were selected and their materials were discussed and supported through evidence the reasons for their preference and there corresponding component. The materials are metallic, ceramics, composites, and polymers. Each category was discussed against the component that the make in auto industry. Thereafter, the report provided a criteria employed by manufacturers, designers and engineers in the selection of materials. The criteria entails factors that determine which material makes what and they include weight, economic feasibility, safety, cost, and recyclability. The WHO, WHAT, HOW, WHO criteria was also demonstrated. Next, the material identified were tested by two methods Jominy-End quench and Hounsfield tensile. The objective of these examinations was to establish the qualities and factors that render a particular material appropriate for its selected role. Lastly, form the test results found in the two tests and after comparing them with the BS/EN standards, and other sources regarding steel – a suitable for making a steel-support pin is established. Table of Contents Summary 2 Introduction 4 1.0.Report and Analysis 4 1.1.Task 1 4 1.1.1.Weight 4 4 1.1.2.Safety 5 2.1.1.Recyclability 5 3.1.1.Economic Efficiency 5 4.1.1.Process for Selection of Materials 6 4.2.Task 2 8 Modern Vehicle Materials 8 4.3.Task 3 13 4.3.1.Metallic: Engine 13 4.3.2.Ceramics: Brake Disc 16 4.3.3.Composites: Chassis 17 4.3.4.Polymers: Body Frame 18 4.4.Task 4 18 4.4.1.Hounsfield Tensile Test 18 4.4.2.Jominy-End Quench Test. 19 4.5.Task 5 23 4.5.1.Suitable Material for Steel Support Pin 23 References 24 Introduction The herein report entails a study of various material particularly employed in the auto industry. The objective is to determine the criteria employed by designers and engineers to select a particular material for a give vehicle component. As such report is split into two parts; the first scrutinises materials used in auto industry whereas the second part experiment and tensile on selected materials and then the data be compared with other sources 1.0. Report and Analysis 1.1. Task 1 In the selection of materials for use in the auto industry, a number of factors are considered. The variety of materials available are used in making auto parts such as the roof, doors, and chassis. However, the design part calls for other consideration rather than picking any other material. The key factors include; Weight (should be lightweight) Safety Economic efficiency Recyclability And life cycle criterion Legislations and regulations Customer requirements 1.1.1. Weight Considering the emphasis on reduction of emissions, improvement of fuel efficiency and reduction of greenhouse effects, weight of material used in auto industry is very significant. For instance, experiments have shown that lightweight materials facilitates efficient fuel use. In fact 10 % of weight reduction leads to about 7 % improvement in fuel efficiency (Nayyeri, 2015). Thie weight reduction is arrived at through i. Replacement of high specific weight with low weigh materials without compromising on durability and rigidity i.e. replacing steel with aluminium ii. Optimization of the load-carrying parts in terms of strength and durability Changing the production processes and reducing weak joining methods such as spot welding (Nayyeri, 2015). 1.1.2. Safety 2.0. Safety as another consideration demands that vehicles manufactured are crashworthy. This is the ability to withstand impact and be able to survive for passengers. The material should have the potential to absorb energy via controlled failure mechanisms. 2.1.1. Recyclability 3.0. There are several measures currently to ensure that there is protection of resources, negligible CO2 emissions, and recycling of material within the auto industry. For instance, in the UK, about 1 – 2 million vehicles terminate their life annually as they are considered a hazard and waste unless treated (Nayyeri, 2015). Therefore, materials selected for vehicles should be recyclable. 3.1.1. Economic Efficiency 4.0. The cost of materials is one of the key determinants of the type of material adopted for any vehicle component. Cost of materials entails the actual cost of individual material, cost of designing a part, and the cost of testing a product. For instance, magnesium and aluminium alloys are expensive that the tradition cast iron and steel. As such, the move to select an expensive material should be justified by improved functionality and efficiency (Nayyeri, 2015). 4.1.1. Process for Selection of Materials Whereas there are many methodologies regarding the selection of materials for the auto industry, Claus Razin’s criteria stands out. The criteria is best shown using the following triangle (Andrea & Brown, 1993). With the acknowledgement of the need to achieve outmost value, Claus shows the compromises and trade-offs that vehicle manufacturers consider which include component cost, performance, material, production actions necessary attain excellent vehicle design. With respect to above factors, an equilibrium has to be struck when selecting material to achieve the best technical structure at maximum economic returns. As well, the best approach to material selection must ensure that the three values (performance and styling, manufacturing costs and constraints, and material and component costs) are at bar (Andrea & Brown, 1993). As such, the engineer has to only consider the material properties but the qualification of such materials for the manufacturing procedures. Therefore the material selection involves the material attribute as described below From the above explanation, a systematic approach of material selection is appropriate to arrive at component that best serves the purpose and economically produced. A systematic approach follows the WHY, WHEN, WHO, and HOW criteria (Sandström, 2010) WHY This is the first step in the systematic material selection criteria. It involved in material selection to ensure that the designed vehicle function at best and at minimal cost. The step ensures that engineering materials are fully utilized, avoids needless expensive structures, and guarantees minimal failure at any given time (Sandström, 2010). Actually, by asking oneself why material A or B, the objective of the designer is to establish very minimal cost for producing a vehicle while ensuring all requirements such as safety, weight and so on are satisfied (Sandström, 2010). Keen consideration has to be invoked to demonstrate the value of weigh reduction in transport application. WHEN The WHEN step presents the actual time when material selection is done. It is when the vehicle components are first designed. The rationale behind this step is that in case new material are called in, there is need for modification so as to configure with design parameters. When done earlier, it means that if failures surface earlier enough, the designer can change the material. Such compelling material substitution are usually costly and should be avoided by ensuring the original design is excellently done (Sandström, 2010). As well, material selection and substitution when necessary should be done even when a component is redesigned. WHO This step entails knowing who is involved in selecting materials used in vehicle manufacturing. Often a design engineer(s) is the person given the responsibility of developing a particular vehicle component. It is advisable that the designer calls in other experts to achieve optimal results (Sandström, 2010). HOW Probably the most use part of the systematic criteria in material selection, this step takes a step further in establishing how the vehicle will be manufactured. It is summarily contains 5 steps Formulation of the specific function of a particular component such chassis, rims, windows frames and so fort Matching of vehicle specifications to material(s) properties Analysis of the repercussions of respective material use Optimization of the material choice Optimization of component geometry (Sandström, 2010) 4.2. Task 2 Modern Vehicle Materials 4.2.1. 6 Metallic Materials (component and criteria) Gear box/engine 1. Steel Used to engine blocks and a large part of both the gearbox and engine are made of steel. Stainless steel is for instance used to make pistons. Criteria – The use of steel is due to its inherent ability to grip impact energy whenever a crash occurs. It is very strong. It is also favoured compared to its peers is its low cost. 2. Iron –carbon alloys Used in both gearbox and engine to fabricate components such as face gears, differential gear casing, valves and gearbox-selector forks. Criteria – it selected as candidate due to fact that its alloys possess high stiffness, and tensile strength. 3. Aluminium Al to make gearbox housings, engine frames, engine cylinder head and engine brackets. Criteria: It used here due to its ability to reduce vehicle weight and its capacity to provide high energy-absorption performance. Elsewhere 1. Magnesium Use: Steering columns, seat frames, wheel rims, fan casing and brake brackets (Orłowicz et al., 2015). Criteria – it is preferred currently in auto industry due to its low weight that both aluminium and cast iron by 33% and 75% respectively. Other merits include better machinability, longer life, and faster solidification (Todor & Kiss, 2016). 2. Titanium Titanium is utilized in making valve springs, exhaust systems, connecting rods and rotating components such as the crankshaft. Criteria – It is particularly used in vehicle components that produce or experience very high temperatures, and where high strength is a prime requirement. 3. Sintered metals Use: making Valve seats Criteria – Sintered metals is a combination of molybdenum, nickel, chromium, cobalt, carbon, titanium, magnesium, and zinc used a lubricant (Orłowicz et al., 2015). Due to this combination of individual properties of each element, sintered metals have best performance ability compared to rest of materials. 4.2.2. 2 Ceramic Materials 1. Zirconia Use: Brake Disc Criteria – when stabilized with Yttria, zirconia is favored due to its high strength and resistant to high temperatures more than some metals. 2. Alumina Use: Vehicle body polishing and as a catalytic substrate Criteria – it has both high chemical resistance and mechanical strength, excellent electrical properties and dimensional stability even at high temperatures. It ensures outstanding reliability with less maintenance effort over the vehicles lifetime 4.2.3. 2 Composite Materials i. Carbon-Fibre Epoxy Component – Chassis Criteria – This material is resistant to corrosions and provides better strength and stiffness. As well, they facilitate efficient vehicle fuel consumption since they help in weight reduction and still meets strength needs (Todor & Kiss, 2016). ii. Glass-fibre Use: Body frame Criteria – Significantly preferred in sports car such as Formula 1 because it is lighter compared to conventional materials such as steel and aluminium. Glass-fibre is easily shaped and resistant to corrosion. It is also cheaper when production focusses on small quantities (Fuchs et al., 2008) i. 4 Polymer Materials 1. Polycarbonate (PC) Component: Lights and lenses (both front and rear) Criteria: PC is very transparent and has the capacity to be painted into different shades. It also a good electrical insulator. Besides, it possesses excellent dimensional stability, toughness, and good precision (Gospocic & Bartulic, 2005) 2. Linear polyester Component: Radiator grilles, door-handles, and rear-mirror housings Criteria: Besides being highly resistant to chemical attack, L polyester has good sliding and insulation properties, very strong and opaque (Gospocic & Bartulic, 2005) 3. Acrylonitrile/butadiene/styrene (ABS) Component: Housings and Linings Criteria: ABS is a very durable thermoplastic that is resilient to both weather and chemical attack. It has a rubber-like feature that gives it good impact resilience hence its application in the auto industry. 4. Polyvinyl chloride (PVC) Component: Internal lining and cable coating Criteria – PVC is widely accepted due to its good resistance to both solvent and chemical attack. Presence of vinyl accords it excellent tensile strength that makes it appropriate for covering linings. 4.3. Task 3 4.3.1. Metallic: Engine Composition A vehicle’s engine block comprises of a number of components which include cylinder head, valve cover, inlet manifold, and cylinder block as shown above. Often the components are made of different metallic metals such as aluminium, cast iron for valve cover and inlet manifold respectively. Characteristics The engine’s characteristics are generated from the materials used in making the components. Its features include Cylinder Block – this is made from Cast iron (gray) as shown in picture above Cylinder Head and liners – made from Cast iron as well Valve cover, piston and inlet manifolds – made from aluminium casting Crankshaft and camshaft – made from steel forging Properties The properties of the engine block are those of individual materials used in its construction Cast iron The cast iron used for the block, cylinder heads, and liners has a combination of about 3%, 1-3%, 0.2-1%, 0.255, and 1% traces of carbon, silicon, manganese, Sulphur, and phosphorus respectively. The traces of the gray cast iron offers it excellent wear resistance, good damping absorption, easy machinability and less costly Aluminium casting Aluminium alloy is used to make Valve cover, piston and inlet manifolds and since these materials demand high precision and lighter, the properties that make Al favourable include the following Compared to cast iron, it has good machinability. Two alloys are particularly used in engine block manufacturing (A319 and A356) The alloys have traces of manganese, titanium, silicon, copper and iron, the alloy develops good casting properties such as good thermal conductivity. With treatment, it develops high rigidity and strength Steel forgings Used in making crankshaft and camshaft which demand very tough yet strong material. Steel forgings It is credited with malleability. It can sustain beyond the yield point It offers vibration resistance due to its ability to absorb extreme vibrations. This is useful to deter vibrations within the engine block. Manufacturing methods A myriad of methods are involved in the manufacturing of engine block since each component demands unique method. 1. Die casting This is a method of pouring molten metal into a mould and let to solidify. The solidification takes place at two stages; crystal growth and nucleation. The mould is made in the shape of engine block Make the pattern Two halves of the mouldi Mould with all halves glued together The core contains the water jacket, the gas escapes via the pink core Molten metal is poured through a front centre hole and then fills the entire mould by using risers Rough produced block Complete engine block 4.3.2. Ceramics: Brake Disc Composition: a ceramic-based brake disc composed of carbon-fibre that is reinforced with silicon carbide. Characteristics: Brake disc made from ceramics are lighter compared to convention cast iron ones. They weigh almost 50% less With ceramic-based brake disc, the brake response in improved There is an excellent pedal feeling, improved steering action, and high resistance to abrasions thus durable. Properties Low weight Excellent toughness Resistant to thermal-based shocks and Quasi-durability Manufacturing methods They include i. Mill balancing – this process helps in flattening the disc on both sides and can as well be called surfacing. The objective is to manufacture a balanced & seamless disc so that it will not vibrate while running (Wilhelm, 1993) ii. Ground Finish – A manufacturing process dedicated to smoothening of disc ends and modeling the disc to run effortless. iii. Holes chauffeuring – is method of smoothening edges of holes to diminish the wearing of the braking pad (Todor & Kiss, 2016). iv. Holes casting – the holes are casted rather than drilling them and then the burrs are removed later. Casting is preferred as it makes the disc stronger and durable. 4.3.3. Composites: Chassis Composition – a Composite chassis is commonly composed of carbon, Kevlar and glass fibres and therefore, its properties and characteristics take those of individual materials. Characteristics/ Properties Low density Due to toughness and strength, composites such as fibre are able to withstand stress Composite epoxy such as carbon-fibre provides high strength/low weight quotient making them applicable in racing cars (Fuchs et al., 2008). Manufacturing methods 1. Part drawing 2. Modelling 3. Structural Analysis 4.3.4. Polymers: Body Frame Composition: Characteristics/Properties - It possesses excellent dimensional stability, toughness, and good precision (Gospocic & Bartulic, 2005) - Besides being highly resistant to chemical attack, L polyester has good sliding and insulation properties, very strong and opaque Manufacturing methods 4.4. Task 4 4.4.1. Hounsfield Tensile Test a) Hounsfield tensile test. Material: Aluminium Introduction: The experiment starts by first computing the maximum load that is to be applied of an aluminium specimen. Therefore, the report will involve determination of Ultimate-tensile stress (UTS), yield stress, and the percentage of elongation. It also elaborates on the why it is hard to obtain a reliable strain as well Elasticity moduli. Procedure i. The specimen was measured and its diameter and length recorded. Proper concentration was necessary to avoid parallax errors. This step was done twice and the result averaged before recording to eliminate errors. ii. The specimen was then loaded unto the Hounsfield machine iii. A load of weight that is about 75% that of yield was used and this ensure that the specimen is completely seated in the jaws. iv. The load was released and we also set the mercury indicator v. A paper was added to the chart rolled and the test began. The test continued until when the specimen napped. vi. The paper was removed and then the % of elongation of the specimen was measured. Result The graph is as below 4.4.2. Jominy-End Quench Test. Material: Steel Introduction The aim of mechanical test is to establish the hardenability of steel used in manufacturing of engine and gearbox in cars by use of Jominy-End-Quench Test. While hardness is the capacity of a material to resist abrasion or scratch, hardenability is the capacity to withstand deformation whenever a load is applied to a material. The knowledge gained from this test is useful in the selection of best material and corresponding heat treatment procedure to reduce thermal stresses in the vehicle components made. Procedure 1. A sample specimen steel cylinder measuring (100mm x 25mm) was obtained and prepared for testing 2. The second step involved normalization of steel to remove the variations in microstructure that resulted out the previous forging and then followed by austenising. The latter was carried out at around 750-900 °C 3. Thirdly, since Jominy requires that a specimen be heated to very high temperature, we rapidly transferred the specimen to reduce energy transfers. Upon removal from the oven, the specimen was clapped onto the testing machine, held vertically and water sprayed uniformly from one end at bottom to the other at the top. 4. Since the cooling decreased from the bottom end upwards, it was possible for us to measure the effect of varied cooling rates from the rapidly quenched end and the air cooled at the top. 5. Ground flattening was done on the specimen at a depth of 0.40 mm to scrap the decarburised material. 6. The hardness was then measured at the interval of 10 mm (10 stances for the 100mm piece). 7. Finally a Rockwell hardness test was carried and the values obtained were used to plot hardness versus distance (from the rapidly quenched end) RESULTS JOMINY POSITION (mm) Rockwell hardness 10 65 20 62 30 58 40 59 50 56 60 53 70 50 80 47 90 42 100 37 Discussion The quenching of steel leads to the formation of austenite and transforms it martensitic. This transformation is very rapid and therefore, there isn’t enough time for carbon to fully come out of the martensitic structure. The data and graph obtained shows that hardness increases as the test was done towards the quenched end of the steel cylinder. The fluctuations of up and down in the graph are due to test errors such as Poor time of transfer between the oven and quenching media Temperature gradients and General material imperfections Conclusion As well demonstrated in this experiment, the Jominy Test enabled us to test hardness of material cooled at different rates. Besides the time taken for quenching, hardenability is influenced by the alloy composition of the material tested. It is also influenced by the processing steps such as austenitisation temperature. Overall, the rate of cooling determines the kind of hardness found in treated steel. The faster it cools, the harder it becomes. 4.5. Task 5 4.5.1. Suitable Material for Steel Support Pin A steel-support pin has to be very strong and if it has to have a hardness value of 32 and ultimate-tensile strength ranging between 805 and 1000 N/mm2, then from BS/EN standards, High-tensile steel (AISI 4140) qualifies It has a UTS of about 950MPa and yield of about 800MPa AISI 4140 supplied has UTS of 850-1000MPa in heat treated state from one end upto about 100mm At this state, it possess high tensile, outstanding toughness, and machinability. From the results obtained in the Jominy quech method, it was found and evidenced that when a material is treated by quenching from one end, its hardness reduces as the rate of cooling reduces As with other sources, widely, the properties of AISI have demonstrated superior qualities in producing tough and durable parts. Due to the presence of elements such molybdenum, manganese, and chromium within it, AISI 4140 has excellent fatigue strength, toughness, and good resistance to scratch and impact (azom.com, 2012). Regarding treatment, AISI 4140 steel can be heated to about 850 °C and then quenched into oil media. Prior to this treatment, it can be normalised by further subjecting it to heat to about 900 °C for sustainable time and then followed by cooling in air (azom.com, 2012). From the comparison and resultant concurrences among areas of consideration, AISI 4140 fully qualifies for the construction of a steel-support pin. References Andrea, D.J. and Brown, W.R., 1993. Material selection processes in the automotive industry (No. UMTRI 93-40-5). Azom, (2012). AISI 4140 Alloy Steel (UNS G41400). [online] AZoM.com. Available at: http://www.azom.com/article.aspx?ArticleID=6769 [Accessed 18 Mar. 2017]. Fuchs, E.R., Field, F.R., Roth, R. and Kirchain, R.E., 2008. Strategic materials selection in the automobile body: Economic opportunities for polymer composite design. Composites science and technology, 68(9), pp.1989-2002. Nayyeri, P. (2015). Materials for Automotive Body and Chassis Structure. [online] Linkedin. Available at: https://www.linkedin.com/pulse/materials-automotive-body-chassis-structure-pooyan-nayyeri [Accessed 18 Mar. 2017]. Orłowicz, A.W., Mróz, M., Tupaj, M. and Trytek, A., 2015. Materials used in the automotive industry. Archives of Foundry Engineering, 15(2), pp.75-78. Sandstrøm, R., 2010. TALAT Lecture 1502: Criteria in Material Selection. Štrumberger, N., Gospočić, A. and Bartulić, Č., 2005. Polymeric materials in automobiles. PROMET-Traffic&Transportation, 17(3), pp.149-160. Szeteiová, K., 2010. Automotive materials plastics in automotive markets today. Institute of Production Technologies, Machine Technologies and Materials, Faculty of Material Science and Technology in Trnava, Slovak University of Technology Bratislava. Todor, M.P. and Kiss, I., SYSTEMATIC APPROACH ON MATERIALS SELECTION IN THE AUTOMOTIVE INDUSTRY FOR MAKING VEHICLES LIGHTER, SAFER AND MORE FUEL–EFFICIENT. Wilhelm, M., 1993. Materials used in automobile manufacture-current state and perspectives. Le Journal de Physique IV, 3(C7), pp.C7-31. Read More

For instance, in the UK, about 1 – 2 million vehicles terminate their life annually as they are considered a hazard and waste unless treated (Nayyeri, 2015). Therefore, materials selected for vehicles should be recyclable. 3.1.1. Economic Efficiency 4.0. The cost of materials is one of the key determinants of the type of material adopted for any vehicle component. Cost of materials entails the actual cost of individual material, cost of designing a part, and the cost of testing a product. For instance, magnesium and aluminium alloys are expensive that the tradition cast iron and steel.

As such, the move to select an expensive material should be justified by improved functionality and efficiency (Nayyeri, 2015). 4.1.1. Process for Selection of Materials Whereas there are many methodologies regarding the selection of materials for the auto industry, Claus Razin’s criteria stands out. The criteria is best shown using the following triangle (Andrea & Brown, 1993). With the acknowledgement of the need to achieve outmost value, Claus shows the compromises and trade-offs that vehicle manufacturers consider which include component cost, performance, material, production actions necessary attain excellent vehicle design.

With respect to above factors, an equilibrium has to be struck when selecting material to achieve the best technical structure at maximum economic returns. As well, the best approach to material selection must ensure that the three values (performance and styling, manufacturing costs and constraints, and material and component costs) are at bar (Andrea & Brown, 1993). As such, the engineer has to only consider the material properties but the qualification of such materials for the manufacturing procedures.

Therefore the material selection involves the material attribute as described below From the above explanation, a systematic approach of material selection is appropriate to arrive at component that best serves the purpose and economically produced. A systematic approach follows the WHY, WHEN, WHO, and HOW criteria (Sandström, 2010) WHY This is the first step in the systematic material selection criteria. It involved in material selection to ensure that the designed vehicle function at best and at minimal cost.

The step ensures that engineering materials are fully utilized, avoids needless expensive structures, and guarantees minimal failure at any given time (Sandström, 2010). Actually, by asking oneself why material A or B, the objective of the designer is to establish very minimal cost for producing a vehicle while ensuring all requirements such as safety, weight and so on are satisfied (Sandström, 2010). Keen consideration has to be invoked to demonstrate the value of weigh reduction in transport application.

WHEN The WHEN step presents the actual time when material selection is done. It is when the vehicle components are first designed. The rationale behind this step is that in case new material are called in, there is need for modification so as to configure with design parameters. When done earlier, it means that if failures surface earlier enough, the designer can change the material. Such compelling material substitution are usually costly and should be avoided by ensuring the original design is excellently done (Sandström, 2010).

As well, material selection and substitution when necessary should be done even when a component is redesigned. WHO This step entails knowing who is involved in selecting materials used in vehicle manufacturing. Often a design engineer(s) is the person given the responsibility of developing a particular vehicle component. It is advisable that the designer calls in other experts to achieve optimal results (Sandström, 2010). HOW Probably the most use part of the systematic criteria in material selection, this step takes a step further in establishing how the vehicle will be manufactured.

It is summarily contains 5 steps Formulation of the specific function of a particular component such chassis, rims, windows frames and so fort Matching of vehicle specifications to material(s) properties Analysis of the repercussions of respective material use Optimization of the material choice Optimization of component geometry (Sandström, 2010) 4.2.

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